Useful Notes / Heresies and Heretics

Below is a list of well-known heresies and heretics found within real-life religions, and NOT an outline of a Warhammer 40,000 variant.

For fictional examples, go to The Heretic.

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Examples

Famous Heresies in the Catholic Church

• The Catechism of the Catholic Church has an official definition of heresy, which it juxtaposes against its definitions of incredulity, schism, and apostasy.
  Incredulity is the neglect of revealed truth or the willful refusal to assent to it. Heresy is the obstinate post-baptismal denial of some truth which must be believed with divine and Catholic faith, or it is likewise an obstinate doubt concerning the same; apostasy is the total repudiation of the Christian faith; schism is the refusal of submission to the Roman Pontiff or of communion with the members of the Church subject to him" (CCC 2089).
  • You may have noticed something important in that definition—the heresy is only a heresy when it knowingly and willfully contradicts established Catholic teaching, and a person is only a heretic if he/she holds a heretical belief and has had valid (i.e. Catholic, or Orthodox, probably) baptism. The Catholic Church has a habit of not granting strict definitions to doctrine until it becomes a major issue, due to issues of opportunity and urgency—the divinity of Christ, while held and intuited by a large portion of Christians to varying degrees, wasn't formally defined until after Constantine legalized Christianity in the early 4th century, for example.
  • This definition also clarifies the position of heretics vis-a-vis Catholics and other non-Catholics:
    • A Catholic is one who has been validly baptized (according to Catholic rules), believes in Church doctrine, and recognizes the authority of the Church hierarchy.
    • Someone who was never validly baptized (again according to Catholic rules) and never believed in what the Church considers true Christian doctrine is incredulous. Thus most people raised as non-Christian or raised as Protestants (as they have strong disagreements on issues of doctrine and from the Catholic perspective are not considered to have had valid baptisms) are "incredulous" from the Church's point of view.
    • Someone who has been validly baptized and believes in Church doctrine but does not recognize the authority of the Pope is schismatic. The clearest example of this is the Eastern Orthodox church, who agree with Rome on virtually every doctrinal point and whose baptisms are at least arguably valid from the Catholic point of view but disagree on whether Papal authority is legitimate. The status of the "Patriotic" Catholic Church in China is murkier. The communist government of the People's Republic has required Chinese Catholics to renounce the authority of the Pope even as they are allowed to practice their religion while subscribing to more or less the same doctrine as Catholics elsewhere (subject to change under demands by the Chinese government, e.g. on abortion and contraception—that's what the whole "Patriotic" business is about, being willing to bend tenets of their religion to requirements of the government, regardless of what foreigners like the Pope have to say.). Some Catholics consider the Patriotic Catholic Church schismatic, but the Vatican refuses to acknowledge the renunciation and maintains that the Catholic Church in China remains fully Catholic—or, in full communion with Rome, to use Catholic lingo—even if under complicated political circumstances that make formal ties with the Vatican difficult and dangerous.^note This makes the life of non-Chinese Catholics in China much easier—every sacrament at a Chinese Catholic church is accepted as valid by the Vatican. The only problems arise when bishops are consecrated at the order of the Chinese government without Vatican recognition, but even then, informal arrangements are usually made nowadays so that they are not truly schismatic except in rare cases. In other words, most bishops in mainland China today are formally appointed by the Chinese state, but are unofficially recognized by the Vatican. By the same token, the only overt persecution of Catholics in China today is directed at the bishops who openly recognize the Pope while disavowing the religious authority of the Chinese government.
    • Someone who was baptized a Catholic (or, possibly, Orthodox), but has now abandoned Christianity completely is an apostate. This includes Catholics who convert to non-Christian religions (e.g. Kareem Abdul-Jabbar's conversion from Catholicism to Islam) and people who "convert" to atheism (e.g... well... half the famous "Catholics" in America and Europe, really). From the Catholic perspective, it also includes Catholics who convert to Christian sects the Church believes aren't really Christian because they diverge so fundamentally from its understanding of the Christian faith (e.g. William Laurence Sullivan's^note The author of the last book to be banned by the Church conversion to Unitarianism^note At the time still a non-trinitarian Christian sect). (A Catholic who converts to Mormonism—whose Christology and soteriology are singularly bizarre and thus whose position within the Christian tradition is unclear—might be an apostate under this definition.)
    • And only someone who was at one point validly baptized and still considers themselves to be Christian—or even a Catholic—but disagrees with Church teaching on a point of fundamental doctrine is a heretic. For the most part, these are Catholic converts to some of the more-divergent streams of Protestantism (for instance, a Catholic who converts to Pentecostalism is likely to be labeled a heretic, since that sect is still identifiably Christian but differs fundamentally from Catholic teaching on soteriology, the sacraments, and other vital aspects of doctrine). On the other hand, it's not immediately clear that any Catholic convert to Protestantism is a heretic. In particular, a Catholic who converts to High Church Anglicanism might be seen as merely schismatic (given that the High Church interpretation of the "Real Presence" doctrine of the Eucharist is nigh-indistinguishable from transubstantiation, and there are no other major doctrinal differences between High Church Anglicanism and Catholicism). Conversely, Oriental Orthodox Christians, who (at least at first glance) differ with the Eastern Orthodox and Catholics on Christological matters, but whose baptisms might arguably be valid from the Catholic perspective for the same reason that Eastern Orthodox baptisms are, might be regarded as heretics rather than incredulous (which they would be if the Catholic Church regarded their baptisms as invalid) or schismatics (which they would be if their Christology was consistent with Catholic doctrine^note Which it might actually be—see the section on "Monophystisim" below—but the "this is basically a thousand-year argument about semantics" position hasn't been officially adopted by either side and therefore technically both sides regard each other as heretics even though they don't make a point of it anymore and Rome recognized their baptisms).
  • NOTE: Since the following points illustrate the history of the Catholic Church's view of heresies, the point-of-view of the history and reasoning is Catholic. You have been warned.
• An early, biblical example: "But some men came down from Judea and were teaching the brethren, ‘Unless you are circumcised according to the custom of Moses, you cannot be saved.’" -Acts 15:1. This counts as heresy, in spite of dating before most Christian theology was established, since Jesus himself was very explicit that God's grace applied to everyone, not just Jews. "And the faithful of the circumcision, who came with Peter, were astonished, for that the grace of the Holy Ghost was poured out upon the Gentiles also." -Acts 10:45 (Acts 10 is good for general context). Paul also has to deal with the Circumcisers in his Letters to the Romans and the Galatians.
• Gnostic interpretations of Jesus' teachings were declared heretical (in fact, the very word "heresy" was popularized in the Christian world by Catholic theologian Irenaeus with his anti-Gnostic tracts), since it's basically an entirely separate religion that stole some names from Christian theology.
  • Christianity sees the material world as God's direct work which he is truly satisfied with, while Gnosticism carries a general antipathy for the material world, seeing it as a creation of a false god and a prison for people's souls.
    • Building on the above, while Christianity teaches that humans were created wholly by God as part of his creation of the universe, Gnosticism teaches that the Demiurge essentially stole human souls from Heaven/the Pleroma and used bodies to trap them^note Luminous beings are we! Not this crude matter!
    • This antipathy for matter meant that most Gnostics were also Docetists, believing that Jesus didn't really take a human form, it just looked like he did, because he didn't need a human form to tell people reality's cheat codes and it would be pretty much the spiritual equivalent of going undercover among junkies by becoming an addict yourself. Christian theology, meanwhile, is clear that Jesus absolutely did have a human body (in fact, one of the ways he proved his return was because he could still eat and drink) and was killed in a human way, and that if he didn't, that's bad because that meant he never performed a Heroic Sacrifice to save humanity from sin.
    • Speaking of saving humanity, Gnostics believed that salvation came from a sort of mystic revelation called Gnosis; the nature of gnosis varied between sects but was generally something along the lines of 'the material world is evil, but luckily you aren't really material, so if you reject materialism you can get past the archons when you die and reach the Pleroma'. Christianity, on the other hand, teaches that there is no secret or trick that will allow you to bootstrap your own salvation; you have to accept Jesus's Heroic Sacrifice on your behalf.
  • Gnosticism teaches that the God of Abrahamic religion is actually a faker known as the Demiurge who only believes he's all-powerful and whose creation, the material world, is inferior to that of the true deities, the Monad and the Aeons, and who trapped spiritual beings (humans) in his shoddy knock-off world For the Evulz. Often, Jesus is claimed to oppose the god he said was his father by sneaking into the world to give humans the secret to gnosis behind the Demiurge's back. Naturally, early Christians were very unamused with the claims that the God they worshipped as omnipotent, omniscient, and omnibenevolent was a Small Name, Big Ego bully with magic powers.
• Marcionism, which may or may not be a form of Gnosticism depending on what definition is used, was a dualist belief that claimed that the wrathful Old Testament God is a different and inferior being to the loving New Testament God. Developed by Marcion of Sinope, who accordingly rejected all of the Old Testament and most of the New, keeping only the Gospel of Luke (heavily modified by him into the Gospel of Marcion) and St. Paul's letters. Having died in the early 2nd Century, Marcion is one of the very first declared heretics in the Church.
• Sabellianism was a 3rd-century heresy that claimed God the Father, God the Son, and God the Holy Spirit were not distinct individuals who shared the same nature, but the same person doing different jobs. The heresy was also known as Modalism or Patripassianism ("the Father suffered", as a literal interpretation of Sabellianism would imply that God the Father also died on the cross). This doctrine is still affirmed by the modern Oneness (Apostolic) Pentecostal Church and certain Unitarians.
  • Origen, a Christian mystic, was accused of Heresy because some of his ideas were viewed as "too Platonic" for various reasons. Despite popular belief, Universal Redemption was not one of the said reasons.
• Adoptionism, like Sabellianism, preached that God is a singular entity rather than being divided into three. It denies the pre-existence of Christ and claims that he only became divine after being "adopted" as the Son of God at some point (the most common options are his baptism, his resurrection and his ascension). Moreover, it insists that while Jesus has remained divine since his adoption, he is obviously not equal to God the Father. This idea is essentially the opposite of the now-orthodox doctrine that the Son was a divine being who became human, did the Father's will on Earth, and then returned to heaven. While it was once believed that this "adoptionist" or "low" Christology predated the "incarnationist" or "high" Christology and was the mainstream view until the notion of a pre-existing divine Jesus was developed and eventually supplanted the idea that he was merely exalted (adopted as God's son), the current scholarly consensus since the 1970s is that high Christology was developed very early on and coexisted with low Christology. Of course, high Christology eventually won out, and Adoptionism became a heresy. Adoptionism can still be found today, mainly among various strands of Unitarianism and Mormonism.
• Donatism was a 4th-century heresy beginning in the wake of the Diocletianic persecution of Christians (the last official anti-Christian persecution in the Roman Empire) where many Christian clergy had apostatized or handed over holy items to the authorities as a result of coercion. After this, a dispute arose about whether the Bishop Caecilian of Carthage had been properly consecrated. His consecrators were alleged to be among those who had sinned by the acts mentioned previously during the Diocletianic persecution. Donatus Magnus ((270-355), for whom the heresy is named, led the party opposing Caecilian on this basis. They argued that if a clergy member was not in a state of grace, then any sacrament they performed was not valid. He was also consecrated as the Bishop of Carthage because of this and began to re-baptize and re-ordain allegedly lapsed clergy. Donatus was excommunicated for not only this view but due to causing a schism in the Church. St. Augustine of Hippo (354-430) forcefully opposed Donatism, but it persisted even after being declared a heresy. It's unknown when it ended. Later in The Protestant Reformation, some Protestants revived it, causing the Catholic Church to condemn this again with the Council of Trent.
• A very famous example was given to the world in the teachings of Arius, who effectively used orthodox language to teach that Jesus was not divine, but a creature made by God. When Constantine legalized Christianity, one of the first things done by the leaders of the Church was to define and formalize what the belief system of Christianity actually held-Arius, who famously was supported by many bishops and excommunicated by others, gave an explanation of his beliefs to the Council of Nicaea in 325 and was solemnly condemned^note Legend has it that a certain St. Nicholas was also present at the council, and became so angry at Arius' teaching that he punched the man out. St. Nicholas is not included in the official registry of bishops present, but that only adds to the fun.; the Council of Nicaea formally proclaimed the divinity of Jesus Christ. Arianism was also an issue at the First Council of Constantinople in 381, where the divinity of the Holy Spirit was also declared.
  
  Arianism hung around long after this, however, having already been spread by the Gothic missionary Ulfilas to many of the Germanic tribes entering/invading the Empire in the 4th century. Arianism found a particular audience among the East Germanic-speaking peoples; though many West Germanic-speaking tribes (especially the Swabians, Burgundians, and Lombards) were also largely converted to Arianism at first, they switched to Nicene Catholicism quickly when it suited them.^note The biggest West Germanic group—the Franks—had some minor interest in Arianism, but moved to Nicene Catholicism before that got much traction; most of the Frisians were in the same boat. The remaining West Germanic speakers—being the Bavarians (who were too far northeast), the Angles and Jutes (who were in Britain), and the Saxons (some of whom were too far northeast and some of whom were in Britain)—and the North Germanic-speakers of Scandinavia (who were really too far northeast) didn't really get Christianity until a few centuries later, at which point Arianism was long gone. However, the East Germanic-speaking Visigoths (in Spain), Ostrogoths (in Italy) and Vandals (in North Africa) would remain Arian for centuries, and the Vandals, in particular, made persecution of Nicene Catholics state policy for basically the whole existence of their kingdom. (This probably contributed to the bad press the Vandals got from the Catholic world.) The Visigoths and Ostrogoths also engaged in occasional persecutions to show the mostly Catholic locals who was in charge whenever they got uppity. Arianism only really faded away in the 6th century, after the Visigoths converted to Catholicism for political reasons and the Ostrogoths and Vandals were conquered by Justinian's resurgent Eastern Empire. However, hints of Arianism, or less specifically, non-trinitarianism, are still extant with modern-day Jehovah's Witnesses and Mormonism, among other sects.
• Pelagianism was a 5th-century heresy taught by, well, Pelagius, that declared humans morally neutral at birth, and that a human's righteousness or sinfulness was the result of the goodness or badness of the people around them, although goodness was defined as imitating the example of Christ. Pelagius denied the doctrine of Original Sin^note When the first human couple disobeyed God's will (the given story is about Adam, Eve, and the Tree of Knowledge of Good and Evil), they were wholly cut off from the grace of God, and in so doing cut off any children they would have... which means all of us., which, when coupled with Pelagian teaching that Man could reach God under his own power, denied any functional role to God's grace in human nature outside of making holiness easier. Augustine later refuted Pelagianism, but their attempts to reconcile these contradictions led to a belief called "Semi-Pelagianism"... which ultimately landed it in the same boat as its predecessor, as it still held God's grace was not necessary for purposes of salvation (not to mention several other tenets), plus, while human effort alone could not merit the gift of God's grace, it could make some small claim on its receipt. Pelagianism was later revived by some small Protestant sects, and some of the mainstream ones sometimes had a hard time distinguishing themselves from it, as well. In particular, a prominent (if eccentric) Mormon theologian has argued that Mormonism is "entirely Pelagian" in its soteriology (officially, Mormonism is Arminian—which is also heretical from a Catholic perspective—but there's plenty of room for debate).
• Nestorianism, the teachings of Nestorius (there are several of these that share their author's name), and another 5th-century issue, to boot, holds that the Virgin Mary was not in fact the Mother of God^note Theotokos in the original Greek, which literally means "God-Bearer", and only bore Christ's human nature in her womb^note Nestorius proposed Christotokos as a useful term, "Christ-bearer" or "Mother of Christ". A lot of people quickly recognized that this left two Jesuses running around, one man-of-woman-born and one divine, connected via some sort of loosely-defined union. The Council of Ephesus in 431 declared that it was indeed legitimate to refer to Mary as Theotokos, not because she predated or generated God, but because she bore God incarnate. There is some doubt as to whether or not Nestorius himself actually believed or understood the full ramifications of his statements; the Assyrian Church of the East, historically Nestorian, recently signed a joint document on Christology with the Catholic Church and now rejects Nestorianism.
• Monophysitism was largely concurrent with Nestorianism, mainly because it was a powerful reaction to and rejection of it. Horrified by the implications of two Christs running around, the monophysites basically leapfrogged themselves to the other end of the spectrum, claiming Jesus had only one nature^note Greek: mono = one; physis = nature, part divine and part human, something akin to a demigod. This was likewise rejected at the Council of Chalcedon on the grounds that, if Jesus was not fully human, he could not fully participate in and thus represent humanity, and if he was not fully divine, he could not fully participate in and thus represent God; in short, since he was neither truly God or truly Man, he could not join the two, and thus he could not fix the problem of Original Sin (see above), and humanity was still basically screwed.^note Yes, the Catholic Church's official position is that Christ is both completely God and completely Man. Yes, it understands the ramifications of nailing Him to a cross to die.
  
  The modern-day Oriental Orthodox church still affirms Miaphysitism, a moderate form of Monophysitism (or something entirely different, according to them). Very highly simplified, it holds that Jesus has one nature that is both entirely human and entirely divine. How this is at all different from the Chalcedonian position that Jesus has two natures united in one person ("hypostatic union") is the subject of heated academic debate; the possibility that it simply isn't has been suggested as a path to reconcile the two strains of Christology. In any case, the Miaphysite position became common if not standard among "Monophysites" relatively quickly, and so for historical purposes, the two are lumped in with each other.
  
  The endurance of the ancient division is largely a function of politics: the conflict between the Monophysites and the "Orthodox" (that is, the ones adopting the present Catholic—and Eastern Orthodox—Christology) was a hot religious and political issue during the early years of The Byzantine Empire, with Monophysitism being dominant in the empire's eastern provinces (Egypt and Syria, mostly, though it was also adopted by the churches of Armenia^note Which was no longer an independent state (the independent Armenian kingdom had been gone for over twenty years by the time of the Council of Chalcedon in 451) and the Armenian lands had been divided between the Roman and Sasanian Persian Empires. The Armenian Church was, therefore, the only all-Armenia institution remaining, and as a Christian organization, the (Zoroastrian) Persians were always suspicious that the Church was a cat's paw for Constantinople. The theological difference with the officially sanctioned Roman state church helped the Armenian Church show it wasn't aligned with Constantinople and so could operate without too much interference. For its part, Ctesiphon did what it could to encourage Monophysitism in the hopes that the Christological dispute would lead the Armenian Church to look to Persia for support against Chalcedonian Orthodoxy. (The Sasanian Persians were used to this kind of dancing, having propped up the Nestorian Church of the East in Mesopotamia for basically the same reason. They were actually fairly effective at deploying various religions as tools of power projection more generally, supporting Jewish communities across the Middle East and Manichaeism in Central Asia, both to great effect (at one point, they even got Yemen to convert to Judaism as a move to align with Persia). About the only religion they didn't push was their own orthodox Zoroastrianism.) These efforts proved fruitless in Armenia; it turned out that despite the success of Monophysitism in Armenia, the Armenian Church and the Armenians more generally really were more inclined to favor the Romans over the Persians in secular affairs when they could help it. and Ethiopia^note Which was was not a province but a valued ally of Byzantium against Persian interests in Yemen and the Arabian Peninsula more broadly. Ethiopia attacked Yemen about 130 years after the conversion to Judaism basically to add another front to the wider war between the Romans and Persians. (They would hold onto Yemen until the rise of Islam a generation or two later made the whole Roman-Persian contention irrelevant.) The Ethiopian church was administered through the Monophysite Patriarchate of Alexandria in Egypt. This suited the Ethiopian monarchy and church just fine, as it insulated the Ethiopian Church from Constantinople's (and thus the Emperor's) influence while keeping them clearly aligned with Byzantium against Persia (since Persian policy in the region relevant to Ethiopia was backing Judaism, not Monophysite Christianity).) and Orthodoxy being dominant in the west (in the Greek-speaking heartland of Anatolia and the Balkans/Greece). While the theological differences were genuine and often sincerely held, a lot of the actual heat was more reflective of the non-Greek-speaking East's desire to remain distinct in a Greek-dominated empire, as well as factional power politics; different Emperors backed Chalcedonian or Monophysite clerics at different times for political reasons.
  
  However, when the Muslim Arabs abruptly conquered the eastern provinces, the conflict was basically frozen in the middle of the 7th century because the Caliph didn't care what these Christians believed about Jesus as long as they paid their taxes. The politico-theological games, therefore, ended with the result being that both groups exist as minorities in the mostly-Muslim Middle East while Orthodoxy stamped out the remaining Monophysites in the west as the political calculus changed (namely, the need to present a united Christian front against the expansionist Muslim Arab empire).
• Monothelitism emerged as an attempt at a compromise between the Orthodox position and Monophysitism. This doctrine asserted that Christ had two natures, both human and divine, but only a single divine "will" or "energy." While the doctrine gained some popularity, especially in Syria, it completely failed to mend the schism, because it didn't actually address the issue the two sides disagreed on (or, for that matter, the political issues that the theological dispute was so often a proxy for). Notably endorsed by Pope Honorius I, who was declared a heretic when the doctrine was condemned at the Third Council of Constantinople. This makes him one of the only Popes to officially be declared a heretic by the Church, though this occurred 40 years after his death.
• Iconoclasm ("icon smashing") first showed up in the 7th and 8th centuries. The essence of the claim was that it was sinful to make pictures or statues of Christ and the saints, based on the Second Commandment ("Thou shalt not make unto thee any graven image..."). The Catholic (and Orthodox) view is that God had commanded the creation of religious statues (Ex. 25:18–20; 1 Chr. 28:18–19), including symbolic representations of Christ (cf. Num. 21:8–9 w/ John 3:14). It was originally inspired by the Muslim blanket ban on representations of God and the Prophets (which often ended up as a blanket ban on representational art, just to be safe) and the Old Testament's emphasis against idolatry. Iconoclasts claimed that the Muslim eschewal of images was pleasing to God, as evidenced by the Muslims' military success against all enemies, or at the very least that Christian attachment to images had gotten out of hand and that God had sent the Muslims to punish the Christians for their crypto-idolatry.
  
  Popular history associates this with Byzantine Emperor Leo III "The Isaurian", who had lived near the border with Muslim-ruled Syria, but although this has a grain of truth to it (Leo genuinely was not a big fan of icons), iconoclasm as imperial—and therefore Eastern Orthodox—policy was rather exaggerated by the generation that killed it (with the assistance of the Pope in Rome—at that time, again, the Church in Rome had not yet formally split from the Church in Constantinople, so this fight was basically one within Catholicism—albeit a Catholicism with a focus on the East and one where the Pope was increasingly looking to escape from the Byzantine Emperor's shadow). A good bit of the issue was that icons tended to be richly decorated with gold, silver, and jewels; if the images were destroyed, the State could seize the precious materials, converting the metal into coins and selling the jewels for cash.^note At about the same time, Emperor Wuzong of Tang was doing something similar with the country's great Buddhist bronzes, as well as other Buddhist statutes in gold and silver, as part of his great persecution of Buddhists and other "foreign" faiths. The Chinese state faced less pushback than the Roman, and a truly impressive number of statues were melted down and minted into coin. There's no suggestion that these events had any direct connection, but it's striking that two desperate empires came to similar conclusions in the 9th century. Ironically, it was the Romans that survived, while the Tang had all but collapsed within 60 years of Wuzong's reign. (This isn't to say that the statute-melting doomed them—the liquidity probably helped buy the Tang some of those 60 years, and there's no suggestion that the persecution of Buddhism was a significant factor in the loss of stability—but it is striking.) At the very least, iconoclasts argued, icons were a horrible waste of resources in the face of continuing Arab raids and repeated Arab attempts on Constantinople itself.
  
  Iconoclasm, as a political issue in the Byzantine Empire, lasted from around 726 to 843, with a hiatus from 787 to 814, and wound up - essentially - as a wrangle between Church and State over Imperial power over the Church (the Church won).^note To give an idea of the ongoing effect: Centuries later, another emperor, Alexios I Komnenos, seized icons for their gold in the face of the simultaneous advance of the Turks from the east and Robert Guiscard's Normans from the west. The Church raised the specter of iconoclasm to drum up opposition to this move and seemed likely to raise an uproar. However, they didn't count on Alexios cleverly deflecting these accusations by being crassly materialistic about his grab: he said he had no problem with icons, it was just that the Emperor was empowered to do whatever was necessary--including seize holy images and other Church property--to save Christendom. He also distracted the Church establishment by accusing a prominent philosopher of heresy. Whether or not the icon seizure worked, it certainly didn't doom the nation; Alexios' reign marked the beginning of the last expansion of the Empire. Iconoclasm briefly reappeared in the initial stages of The Protestant Reformation mostly as a pushback against the perceived decadence of the Catholics, but largely disappeared over the years, the only noticeable remnant being most Protestants' tendency to wear a bare cross instead of a Crucifix and building fairly austere and unadorned churches (until the High Church Anglicans decided to up the "High Church" part with the Oxford Movement, though they still don’t do crucifixes as much as Catholics).^note This sets aside the somewhat complicated High Church Lutheranism that formed the state religion in the post-Reformation Nordic countries and some of the German states (particularly the ones around the North Sea). It's really not worth getting into unless you have a particular fascination with Danish or Swedish history.
• Catharism's vogue was in the late 12th and early 13th century. Technically a mixture of Gnostic currents reworked with mostly Christian terminology, there were a few joining principles that connected the various sects under the name. Very similar to Gnosticism above, the Cathars held a fierce antipathy for the material universe, which they held was created by an evil deity (hence, matter is evil), but there exists a Good Deity who should be worshipped instead (there's a resemblance to Zoroastrianism here). One of the largest Cathar sects was the Albigensians, who wielded a great deal of power in southern France during the 13th century, before being obliterated by the French crown and various crusaders in the Albigensian Crusade. They held that the spirit was created by the good God, but imprisoned by the evil one in a physical body. Hence, the bearing of children - the imprisoning of another human soul in a body - was one of the greatest possible evils; logically, marriage and vaginal sex were forbidden, but anal sex might be technically permissible. Since Catharism was believed to have arisen in Bulgaria (among other things, it was connected to another Gnostic sect, the Bogomils), they were also called bougres ("Bulgars") in French, from which we get "bugger" and "buggery" for "anal sex" or someone who practices it. They weren't all about the buggery though; there were plenty of fasts that bordered on wilful starvation and lots of severe mortification was practised. Leaders went about in voluntary poverty. Some sects also seemed to believe in ritual suicide, fasting to death after they had been purified. Catharism has become an extremely contentious topic in recent medieval history, with many arguing that no "Cathar" sect ever existed; local differences in folk religious practice and anti-clericalism were inflated into serious threats to Christendom due to ongoing political crises in southern France.
• Protestantism: You've probably heard something about a Reformation in the 16th century, in which thousands of Christians broke with the Catholic Church. Protestantism is not a specific doctrine or belief-set but rather an umbrella term for thousands of different theological divisions (which can generally be un-splintered into less than two dozen religious "traditions"), that share doctrines of Sola Scriptura (theology should be formed solely by consideration of scripture) and Sola Fide (human beings are justified "by faith alone")^note Centuries of poor definitions and raised tempers led this to be a major point of contention between Catholics and Protestants, who argue over what role "work" has in human entry into heaven; the assumption was that Catholic emphasis on placing "work" besides "faith" led to an overemphasis on the role of human action similar to Pelagianism, which was rejected long ago- it turns out that in the Protestant definition of "faith", the work is a natural product of and inseparable from faith, whereas Catholics refer to "faith" as something along the lines of mere intellectual belief. In short, there's really not much of a difference along those lines, as exhibited when the Catholic Church and a number of Lutheran "bishops" signed a joint declaration of faith several years ago.. The great diversity of Protestantism has two primary roots: a general distrust for human authority and the "doctrine" of private judgment, the latter of which denies the Church its claim to the infallible right to interpret Scripture, and indeed pits the Church against Scripture.
  
  As a point of clarity, while Protestantism is in fact considered a heresy, most Protestants are not considered heretics anymore. Since, unlike the original generation, they were never Catholic in the first place, and because Protestant baptisms are not generally recognized as valid by the Catholic Church, being a Catholic heretic is rather impossible. A convert from Catholicism to Protestantism might be considered a heretic if the particular Protestant sect largely agrees on doctrine but differs on a few key points (e.g. if someone converts from Catholicism to High Church Lutheranism, which is mostly like Catholicism but still holds to the same ideas that made Luther a heretic). Additionally, the position is somewhat complicated by Anglicanism, especially as practised by the Church of England, which was originally intended as - basically - Catholicism where the Church reported to the King, Henry VIII, rather than the Pope (which, ironically, was not terribly different from how the Catholic Spain worked, only simply more overt and extreme).^note Although Spain later came to be known as the workhorse of the Counter-Reformation, their church and, yes, the Spanish Inquisition, reported first to the king and then to the Pope (and the latter was sometimes eschewed on the presumption the king would later report to the Pope himself). In other words, while not rejecting the Pope's authority, in Spain the Church was subservient to the state and not vice versa as in many other Catholic lands of the time. This came to its biggest stretch when Charles V bullied Pope Clement VII into kowtowing to him by literal military force, all while claiming and genuinely considering himself to be the Catholic Monarch. Clement was so upset that his attempts to overcompensate it eventually caused the Henry VIII affair. Even today, the High Church part of the C of E bears a great deal of resemblance to Catholicism. The transition to a fully Protestant church under subsequent monarchs and the according changes in doctrine, ritual, and teaching have derailed attempts at rapprochement. The official position of the Church is that it is "both Catholic and Reformed", i.e. a Protestant church that looks and behaves Catholic. There have been movements within the Church of England to emphasize its Catholic heritage, but the clerics involved tend to either stop short of fully embracing Catholic doctrine or simply convert to Catholicism. One of those movements was the Oxford Movement, which featured the theologians such as Edward Bouverie Pusey and John Henry Newman. Newman himself would eventually convert to Catholicism, to the shock and outrage of the Church of England.
• Jansenism — 17th century. Cornelius Jansen, the bishop of Ypres in what was then French-controlled Flanders (it is today in Belgium), wrote Augustinus, a theological work on Augustine that redefined the doctrine of grace. The Jansenists were a rigorist sect that taught, basically, an adaptation of the Calvinist Protestant soteriology to Catholicism. (Considering that Jansen was originally from the Netherlands, where Calvinist Reformed Protestantism was strong, this is hardly surprising). In this book, Jansen states that man's free will is incapable of any moral goodness. All man's actions proceed either from earthly desires, which stem from concupiscence, or from heavenly desires, which are produced by grace. Each exercises an urgent influence on the human will, which in consequence of its lack of freedom always follows the pressure of the stronger desire. Implicit in Jansenism is the denial of the supernatural order, the possibility of either rejection or acceptance of grace. Accordingly, those who receive the grace will be saved; they are the predestined. All others will be lost. Jansenism was condemned as heretical in five major propositions by Pope Innocent X in 1653. It was re-condemned by Pope Alexander VII in 1656, when Jansenists (notably Blaise Pascal, who wrote the Provincial Letters on the Jansenists' behalf) claimed that their doctrine was misrepresented (that Jansen himself was willing to submit to the Church should it find any errors in Augustinus is another matter entirely).
• Modernism — Late 19th to early 20th century. Modernism is a theological movement spearheaded by Fr. Alfred Loisy and Fr. George Tyrell. It takes its cues from liberal Protestantism^note Notably, however, most early modernists were intensely critical of liberal Protestant scholarship, and regarded themselves as an anti-Protestant tendency. and early modern philosophy like those of Kant and Hegel,^note Though the modernists themselves would famously criticize this intellectual genealogy, insisting that they were influenced by modern trends in Biblical criticism, not philosophy and it teaches that the Christian faith is all based on personal religious experience, individual and collective, and under the influence of the current age. This means that the Church's dogmas can evolve over time, meaning one thing in a certain context and another thing in another. It also proposes that the Catholic Church is not divinely instituted by Christ, but rather a merely human institution formed as a means of organizing Jesus' followers. Pope St. Pius X, seeing that it undermines the nature of divine revelation as a whole, vigorously condemned Modernism as a heresy in 1907 with the publication of the encyclical "Pascendi Dominici Gregis", a condemnation reaffirmed by Pope St. Paul VI in 1964. In 1966 onwards, the work of liberal theologians such as Hans Kung, Edward Schillebeeckx,^note Pronounced SHIL-uh-bakes, in case you were wondering. and Charles Curran was regarded with suspicion by the Church hierarchy on the basis that it represented a revival of the heresy, but while some have been censured or had their doctrines condemned, none of them have been formally regarded as heretics. The relationship between contemporary liberalism in Catholic theology and the historical heresy of modernism is one of the most divisive issues in the Church today and implicates the boundaries of acceptable variation in Catholic teaching that are simply too complex to reproduce in their entirety here.
• Americanism — A lesser-known heresy, largely due to how oddly specific it is, condemned by Pope Leo XIII in a papal encyclical and a letter to Archbishop of Baltimore, the de facto leader of the Church in America. Sometimes called a "phantom heresy", due to heated debate about whether or not it genuinely exists, Americanism was the perception, largely by European clergy, that the church in America was overly individualistic in its approach to religious matters. Put more bluntly, it was the idea that American Catholics were free to decide for themselves which Church doctrines they believed, due to the American culture of religious liberty. Leo XIII was particularly concerned about the American tendency to blithely ignore the Church's social teachings — particularly concerning divorce and economics — and the American attitude towards the vowed priesthood and other religious institutions, which skewed towards the Protestant side of things. The leaders of the American church were, as you might expect, not terribly flattered by this characterization, and denied that it had merit. In response, they asserted that, much like monophysitism above, this one was a proxy for a cultural conflict within the church, namely French and German conservatives projecting their anxieties about growing theological liberalism in Europe onto the church in America (whose hierarchy was diverse, but more Irish than anything else^note Note that because of the historic suppression of the Irish Church by the Protestant English and then British authorities, and the gigantic Irish emigration in the 19th century, the existence of large numbers of Irish priests—let alone Irish prelates—in the United States was something not seen in over 300 years.). Leo XIII himself vacillated on the issue, due in part to being at least somewhat sympathetic to both sides.
• Feeneyism — Quite possibly the youngest heresy on this list, and one of the few true American-born heresies, this one erupted sometime around World War II, when Fr. Leonard Feeney, a Jesuit priest, began to preach a very distorted version of the Church tenet extra Ecclesiam, nulla salus, or "No salvation outside the Church." Feeney taught this to mean essentially that everyone who was not a formally baptized Catholic was, without a doubt, going to or already had gone to Hell, considered heretical due both to the Catholic teaching that it is impossible to know with certainty who is in Hell (or to declare on such matters dogmatically)^note The contrary — the dogmatic declaration of who is in heaven — is fair game and represented through the Church's process of canonizing saints. Even that process is undertaken with a great degree of care and caution, so walking around claiming to know who is going to hell requires a sinful degree of presumption. Polemical depictions of contemporaries in hell — such as can be found in The Divine Comedy — are not necessarily considered heretical, though it probably helps that many of them were still living, so their polemical character was readily apparent. and a denial of several Catholic teachings on the salvation of non-Catholics. Feeney was a notorious and vocal anti-Semite, so the implications of this doctrine, i.e., that Jews were categorically damned, were neither lost on him nor unintentional. The fact that he was also open to declaring anyone who differed with him even slightly a heretic, up to and including a previous Pope, Pius IX, didn't exactly endear him to the church, and his interpretation of nulla salus was NOT from any magisterial authority, but from his private interpretation of Scripture.^note Namely, he interpreted Mark 16 more strictly than was considered acceptable by the Church. Feeney's explanation was that the "true" doctrine had been gradually undermined by renegade clergy. In the end, Feeney was ordered by Pope Pius XII to knock it off and come to Rome to explain himself, and when he refused, he was dismissed from the Jesuits in 1949 and ultimately excommunicated in 1953, an excommunication only lifted as recently as 1972.^note The fact that the excommunication was lifted without a recantation is sometimes used by Feeney's fans as a justification for supporting this view. Needless to say, that's not how excommunication works, and Feeneyism has been consistently condemned by the Church since then. Ironically, the rescinding of the excommunication was probably motivated by a desire not to have an aging priest be denied the final sacraments just for being a stubborn ass, meaning Feeney was a recipient of the mercy he militantly attempted to deny to others.

The Galileo Affair

• "Galileo was famously tried before a court for an issue regarding the veracity of heliocentrism" is about as neutral as the pop-cultural understanding of the actual sequence of events is likely to get; most people seem to think Galileo was declared a heretic, or maybe even tortured for it. Let's start with the context:
  • In Galileo's day, heliocentrism was actually gaining considerable consideration when considering the motion of the stars from an earthly perspective. A Catholic cleric up in Poland^note We won't get into whether he was Polish—The Other Wiki has that covered—but he was definitely working in Poland (his main observatory in Frombork was de facto in the Polish part of Poland-Lithuania). named Nicolaus Copernicus (for whom is named "The Copernican Revolution") famously brought heliocentrism into vogue. He wrote a long text on the subject, On the Revolution of the Celestial Orbs, but put it into the care of a Protestant friend to be published after his death (the book, which contains an excellent account of heliocentricity, was dedicated to Pope Paul III, and its publication was encouraged by Cardinal Nikolaus von Schönberg and Bishop Tiedemann Giese). The friend, a Lutheran clergyman named Andreas Osiander, anticipated the massive ramifications this theory had for Protestant scriptural interpretation (Martin Luther seemed to condemn the new theory^note Luther calling Copernicus an "upstart astrologer" probably didn't help.) and, the likelihood that it might be condemned; to counter this, Osiander prefaced the book with the claim that the descriptions within were theoretical only, and were only employed to simplify computations... something Copernicus never intended.
  • Another proponent of heliocentrism was Johannes Kepler, a Protestant German who expounded on Copernicus' work. Kepler synthesized Copernicus's system with the observations of his former teacher, the Danish (thus Protestant) astronomer Tycho Brahe, and added mathematical precision to both Brahe's observations and Copernicus's system. As he did not couch his developments, Kepler faced opposition from fellow Protestants, but found a welcome reception from a number of Jesuits notable for scientific achievement.
  • It is commonly assumed that Galileo proved heliocentrism — he didn't, exactly, and in fact, he didn't have the scientifical means to do so at the time. He merely made the biggest noise about it. He started by writing a letter in response to the Grand Duchess of Tuscany saying, in effect, "Well, I wouldn't put too fine a point on it, but yes, the evidence does suggest that, scientifically speaking, the Church and Aristotle really do have the whole structure of the Universe wrong." Notice all the hedging: Galileo was convinced, but knew he didn't have definitive, incontrovertible proof. His observation that Venus has phases made it extremely unlikely that geocentrism was true and heliocentrism false, but there were all kinds of other explanations that could have been cooked up to keep the Earth in the middle, even though they were all sort of ridiculous.
    
    The issue was that proponents of heliocentrism were unable to counter the strongest argument against it, which had been proposed by Aristotle himself—if heliocentrism were true, there should be observable parallax shifts in the position of the stars as the Earth moved. Now, there are observable parallax shifts, but the technology to demonstrate that wouldn't be developed until the 18th century—decades after Galileo's death.^note The distance between the stars is several light-years, very large in comparison to Earth's orbit, with a diameter of about 16.6 light-minutes. Until that point, the evidence suggested that the stars' positions were fixed relative to the Earth, and thus, only the Sun, Moon, and other planets were moving. Copernicus' (correct) explanation that the stars were too far away to exhibit visible parallax was not accepted, even by non-geocentrists like Tycho Brahe. Scientists back then, more used to the smaller-sized universe proposed by Aristotle and Plato, fundamentally had trouble wrapping their heads around the great size and vast distances between celestial objects needed to accommodate a heliocentric universe^note Which themselves are minuscule compared to the gargantuan size and mind-numbingly vast distances of the actual universe described by modern astronomy and cosmology, but let's not get ahead of ourselves and proposed a "geoheliocentric" system in which the Sun, Moon, and stars revolved around a stationary Earth, while almost everything else either revolved around the Sun or revolved around something that revolved around the Sun. This system "worked" inasmuch as it didn't contradict the observed evidence (until the parallax shifts were observed), but it was criticized for being more complicated and less elegant than pure heliocentrism. Galileo adopted this critique, but tried to remain restrained in his opinions in the letter to the duchess. However, being a bullheaded and rather stubborn sort of fellow, Galileo later doubled down on heliocentrism, and that got him in trouble.
    • Galileo had a critical role in putting a dent in geocentrism, though. His discovery of The Moons of Jupiter made the Aristotelian theory that much more difficult to defend—if everything was supposed to go around the Earth, why did these four things go around Jupiter instead? And Galileo and other astronomers of his era kept making similar discoveries, particularly (although not necessarily) after they followed his lead in pointing telescopes at the heavens: if the celestial bodies were supposed to be perfectly spherical, why does the Moon seem to have mountains? Or the Sun seem to have spots? (See below for the bad blood that raised.) And why, pray tell (as mentioned) did Venus have phases when you looked at it through a telescope? (The math means that if Venus has phases, things have to be pretty wonky up there if everything revolves around the Earth, with the Tychonic geoheliocentrism being the least-wonky.) And perhaps most significantly of all, why did Brahe—working without a telescope—see a new star (really the supernova SN 1572), when both Aristotle and Church doctrine said that the stars were perfect and thus a new star was impossible? And eighty years later, Edmund Halley noted that even the stars were moving—Sirius, Arcturus, and Aldebaran had moved half a degree since the time of the Classical astronomers and their star charts. Finally, about a century after that—at which point everyone with an education accepted heliocentrism already—someone finally measured the parallax of a star, using a device that amounted to a telescope with extra measuring equipment attached. And that was that for geocentrism.
  • Note also that the Church was in the process of figuring out how to reconcile heliocentrism with their theological teachings, just in case something (e.g. the eventually forthcoming proof of Copernicus' theory that the stars are really far away) made it impossible to argue against heliocentrism on the facts. They'd done this kind of dancing before, and to quote James Burke, explaining away a heliocentric universe would be a "mere bagatelle"—in other words, heliocentrism wasn't a serious threat to orthodoxy. They had gotten pretty far, but weren't quite ready, and thus got annoyed when Galileo started yelling about it. When the aforementioned letter to the Grand Duchess of Tuscany was first shown to a Churchman, the Church's message to Galileo was, in effect, "Would you quiet down a bit? This business is undermining Church authority. It's not that we think you're wrong; it's that you can't tell the people about this right away. Give us time to feed it to them slowly."
  • Unfortunately for Galileo, as we said above, he doubled down on heliocentrism and argued against the literal interpretations of the Bible in the non-theological arena, as it contains passages that explicitly contradicted heliocentrism (the most quoted being the one where Joshua commands the Sun and Moon to stand still over Canaan).^note Although a quick bit of thinking shows even this to be reconcilable: Stopping the Moon is no problem (since it actually does revolve around the Earth, and the Copernican system recognized that), and in a heliocentric system, having the Sun "stand still" over Canaan means "the Earth stops rotating around its axis, making the Sun indeed 'stand still over' Canaan". It was interpretative dances like this one the Church was working on when Galileo began his shouting. Taking to the debate floor, he insisted that the Bible and nature must agree as both proceeded from the same creator, and began insisting Scripture be reinterpreted to suit the theory he couldn't quite prove. Just to make it worse, as Europe was in the midst of the Thirty Years' War, which pitted basically all the Catholic powers of Continental Europe against basically all the Protestant ones, everyone was a bit touchy about religious doctrine, and Galileo's abrasive personality and previous clashes with Jesuit scientists really weren't helping his cause. In 1616, he appeared before Pope Paul V; the pope, weary of controversy, turned things over to the Holy Office, which condemned the theory. Later, Galileo made a request of a friend - Cardinal Robert Bellarmine, a Jesuit; he was granted a certificate that allowed him not to hold or defend heliocentrism, but to conjecture it. Later, he met with another pope (and a personal friend), Urban VIII, in 1623. The Pope granted Galileo permission to write on the subject but cautioned him not to advocate it, instead presenting the arguments for or against it. Not happening. What Galileo actually wrote (in the form of a dialogue), while technically presenting the arguments for both sides, was clearly in favor of heliocentrism, and the arguments against it — including the ones offered by his friend the Pope — were placed in the mouth of the character named "Simplicio" (i.e. "Simpleton"), who was a debater of obviously inferior intelligence and status than the one arguing heliocentrism. Galileo however claimed Simplicio was actually named after Simplicius of Cilicia, a sixth-century commentator on Aristotle, but it's not entirely clear if this is true or he was simply trying to backpedal; given his personality, both are about equally possible.
  • The Vatican assigned two Jesuits, Christoph Scheiner and Orazio Grassi, to look into Galileo's science. Both had solid credentials as astronomers. However, Galileo had managed to alienate both of them. Scheiner was one of the first astronomers to observe sunspots and was, as far as he knew, the first to describe them in a scientific paper (in fact, the first paper on sunspots was published the previous year by David Fabricius, but his paper was unknown outside of Germany.) Galileo attempted to grab the glory of having first seen sunspots from Scheiner, and compounded this by plagiarizing Scheiner in his own paper. Grassi and Galileo, for their part, disagreed on the nature of comets. What made things interesting was that Grassi was right and Galileo was wrong. Grassi had observed a comet over a period of time, and had noticed that the moon moved faster in the sky than the comet did; Grassi correctly assumed that the comet was further from the Earth than the moon was. Galileo believed that they were optical illusions in the atmosphere. Galileo wrote an essay, Il Saggiatore — "The Assayer" — attacking Grassi and his theory. This essay is still taught in Italian schools as a masterpiece of polemical writing. Naturally, having been held up to ridicule, Grassi was no friend to Galileo.
  • Having publicly mocked the Pope and alienated the Jesuits (the Catholic institution most inclined to accept heliocentrism) to boot with attacks on two of their astronomers, Galileo's actions resulted in the famous trial. In course of the trial, Galileo stayed in fine quarters at the Apostolic Palace while his meals were prepared by the best chef in town. While he eventually recanted his teachings, he was not tortured (he was only threatened); he was actually merely placed under house arrest, at a fine mansion in the countryside belonging to a friend, and given a manservant. Galileo was not explicitly declared a heretic, though he was found to be "vehemently suspect" of it; the testimony from his trial (Galileo was tried before an ordinary tribunal) was brought before a group of ten cardinals. Three of them refused to sign his verdict, but his works were eventually condemned.
  • To keep it short, the Church of Galileo’s day issued a non-infallible disciplinary ruling concerning a scientist who was advocating a new and still-unproved theory (and one unprovable with the technology of the time at that) and demanding that the Church change its understanding of Scripture to fit his hypotheses about nature (which it was quietly in the process of doing anyway but wasn't ready to go public yet). At the end of the day, the entire fiasco boils down to an overgrown squabble involving a cranky old man with very powerful friends and a bunch of annoyed bigwigs who decided to cut him down to size. However, the Catholic Church acknowledges its mistake, and has for some time. In 1741, Pope Benedict XIV granted an imprimatur to the first edition of the complete works of Galileo. In 1757, a new edition of the Index of Forbidden Books allowed works that supported the Copernican theory, as science had reached the point where the theory could be proven. Pope John Paul II famously apologized for the fiasco, but there was a second, less well-publicized apology issued about a century earlier; also, the Church has published two stamps in his honor.

Joan of Arc

• Joan of Arc, famous war hero in the conflict between the Armagnacs (a party which included Charles VII of France) and the Burgundians in alliance with the English, was also examined for any possible heretical beliefs.
  • Now, this was by her English captors (with support from the University of Paris, which had English loyalties), who were absolutely desperate to be rid of her — the original round included seventy wild accusations, though they were later replaced with twelve less ludicrous tales and the declaration that the voices guiding her were demonic. When she refused to retract "her wrongs" (which primarily consisted of kicking a lot of English ass), she was threatened with torture and with having her case turned over to the secular authorities (i.e. to let them burn her). At one point, Joan of Arc asked to have her case taken to the Pope himself, and was denied.
  • At one point, her courage did manage to fail her, and she recanted-the official record of the retraction is long (a half-hour read at least) and humiliating in every way possible (and likely more of the same bull; every other account of the retraction mentions she signed a document only a few lines long, including the account from the man who read it to her). Even so, her signature was conditional, only insofar as "it was God's will". Safe for the moment (though her captors were furious), Joan was now stuck in the most dangerous of situations-if she reversed herself on her "recanting", she would be doomed.
  • One of the crimes of which she had already been "condemned" was that of dressing like a man, and it was on this that the English finally slew her, by laying a trap. The reasons for it vary-she may have been trying to protect her modesty from outrage, or her original women's clothes were taken from her, or possibly because she was tired of the ridiculous charade she put on the man's clothes which had been deliberately left for her. In wearing them, she was found and declared to be a "relapsed heretic", and burned the next day (May 29 and 30, 1431; she was 19 years old).
  • 24 years later, her case was reopened, this time with the actual consent of the actual Holy See and the actual attention of the actual pope (as opposed to the original bunch of English bishops led by Pierre Cauchon, Bishop of Beauvais); both the Church and the King of France took a few knocks at the second trial for letting the travesty go so long without addressing it, which speaks well for the second trial's sincerity. However, the common view of her in England (even through the age of Shakespeare) was that she was a witch in league with demons. She was not commonly regarded as sympathetic until the 19th century-compare France, where the opinion that she was divinely inspired was held even during her own lifetime. The case for her canonization was opened in 1869, she was beatified in 1909, and finally declared a saint in 1920.

Other Christian sects/General Mainstream Christianity

• Tsarebozhiye is a small sect in Russian Orthodoxy claiming that Tsar Nicholas II is the redeemer of the sins of the Russian people who was killed as an atoning sacrifice. Adherents claim he possessed a special nature that was free of sin and was made a divine figure after his death, and that his spirit made Russia the Kingdom of God on Earth which prevents the world from following the Antichrist. Obviously, the mainstream Russian Orthodox Church strongly disagrees.
• Positive Christianity was a movement in Nazi Germany that attempted to reform Christianity by incorporating Nazi ideology. Explicitly not dependent on either the Apostle's Creed or the faith in Christ as the Son of God, Positive Christianity attempted to emphasize the "active" rather than "passive" aspects of Jesus' life and recharacterized him as a combative activist who fought the institutions of his day. Like Marcionism, Positive Christianity considered the Old Testament non-canon and associated it with Judaism; unlike Marcionism, this rejection was motivated by racially-based hatred of the Jews as a people. Aryanhood was claimed for Jesus, and one of its main planks was the elevation of Aryans, especially Nordics. Positive Christianity was created more for political reasons than religious ones; many leading Nazis were hostile towards Christianity, some believing it had been perverted and others rejecting it altogether. However, due to the political significance of Christianity in Germany, moves against its churches had to be made in stages. While attempts were made to unify German Protestantism into a Nazified German Evangelical Church, they met with widespread opposition and most German Protestants didn't side with those promoting Positive Christianity. After the Nazi regime fell in 1945, Positive Christianity faded into obscurity, though some Christian Identity groups espouse its tenets.

Islam

• Islam has very strict instructions on what its followers should and shouldn't do, and practices that can't be traced back to the Prophet Muhammad himself^note Or at least, that which goes against the spirit of Islam - there was no Internet in his time, but that doesn't make the Internet forbidden are regarded as heretical, or bid'ah-literally meaning "innovation" (since the religion is considered to have been perfect when revealed, so anything added later would make it less perfect; "bid'ah" outside of religion is OK, although usually other terms are used).
  • Ahmadiyyah. Its followers believe that the aforementioned Ahmad is also a Prophet, which goes against the role of Muhammad as the final prophet bringing final scripture. Numerous conflicts, some of which were violent, have happened between Ahmadiyyah and the more mainstream Muslims. It doesn't help that it originated during the British Colonial era and the early followers had ties with the Colonial authority-the present headquarters of the Ahmadiyyah are in the UK.
  • Sufism. A rather loose term for mystical sects than put more emphasis upon the spiritual experience and, usually, are less strict on religious laws—some Sufi tariqas (literally "ways", usually translated as "orders" or "sects") even use alcohol or other psychoactive drugs (particularly cannabis) in their rituals, even though orthodox Islam regards these as makruh (discouraged) if not outright haraam (forbidden). It might have been influenced by Hindu and Buddhist mysticism, which shows in their meditative practices, worship rituals and panentheist-sounding theology. Sufi imams have considerably greater influence on their followers than the mainstream imams. Their departure from what mainstream Muslims consider within bounds varies, and reactions from mainstream Muslims vary between "that is actually kind of legitimate, even if we don't worship like that" to "let those eccentrics be, as long as they don't cause trouble" to "those are pseudo-Islam, exterminate them." The first attitude is most common among poorer, less educated Muslims, since Sufism is similar to the folk Islam they practice (loaded with saints and shrines and so on), while higher-class/more educated Muslims tend to gravitate toward the second interpretation (essentially regarding Sufism as a somewhat overblown but still basically orthodox and more or less harmless version of folk Islam), and the ultra-purist Wahhabis love knocking down Sufi sites whenever they get a chance.
  • Sunni and Shi'a Muslims don't generally regard each other as heretics, as the difference was mostly a political one rather than a theological one. Comparison can be drawn between Catholicism and the Eastern Orthodox Church, more or less.

Judaism

• The original Nazarene sect was considered a heresy in Judaism. Only once they started recruiting non-Jews without putting them through the proper conversion rituals did Christianity become a distinct religion, whose differences initially amounted to that before deepening over time. Modern Messianic Judaism, or groups who claim to be Jews who believe Jesus is the messiah, is still considered a heresy and more or less a form of Christianity dressed up as Judaism. What sealed the break was the expelling of the Christians from the synagogues in AD 82. Up until this point, relations were tense, but it was still a common practice for an Israelite Christian to go to the synagogue on Sabbath morning, and then go home, rest up, and attend Mass in the evening. After the expulsion, Christians no longer regarded themselves as a sect of Judaism, even if they were raised as Jewish.
• Karaism is a sect of Judaism that rejects the Oral Law, and accepts only the Written Law, a major difference between it and Orthodox Judaism. Once a fairly widespread movement, it has dwindled but there are still a handful of Karaite communities around today, mostly in Israel.
• The Essenes were a sect contemporary with Jesus that believed in a spiritual war between good and evil. They are best known for writing the Dead Sea Scrolls. (No, not those.) It's thought that John the Baptist (see The Four Gospels) may have belonged to the Essenes or was at least influenced by them, since some groups of them placed a lot of importance on baptism.
• Orthodox Judaism, which was codified by the rabbis who wrote The Talmud after the Second Temple in Jerusalem was destroyed by the Romans and the Jews were forced into exile, sees itself as the true Jewish religion in an unbroken tradition going back to Moses himself. Other Jewish sects that existed around that time, like the Essenes and Zealots, have long since died out. For most of the last two millennia it was more or less the only form of Judaism, other than the Karaites, and is still the sect with the most members. In the last couple of centuries other Jewish denominations have come into being like Conservative Judaism (which is traditionalist like Orthodox Judaism, but not as strict), Reform Judaism (which is progressive and not strict about Jewish law) and Reconstruction Judaism (which sees Judaism as less of a religion and more of a culture). Orthodox Judaism sees all of these as heresies, and conversions to them are not accepted by Orthodox rabbis, but they may still be seen as ethnic Jews who can return to Judaism at any time if they undergo a proper conversion. Orthodox and Conservative Jews tend to agree on more and get along better than Orthodox Jews do with Reform or Reconstruction Jews, who tend to agree more with each other.
• In Orthodox Judaism, there are also divisions with Modern Orthodox Jews being less strict than Haredi Jews (often called "ultra-Orthodox" in English even though they dislike the term), who are The Fundamentalist and are somewhat like the Jewish equivalent of the Amish. A subset of Haredi are the Hasidic Jews, who formed in the 17th century and have a spiritual and mystical approach to the religion instead of the rationalist and legalistic approach of Modern Orthodox rabbis. Hasidism was once strongly opposed by other Orthodox Jews who saw it as heretical, but today relations are much better between them since both accept each other as fully (in a religious way) Jewish. Because the Hasidim are from eastern Europe and many of them now live in the United States, they have been a big reason for the All Jews Are Ashkenazi stereotype in North America of Jewish men having large beards and wearing all-black clothing and wide-brimmed hats, and speaking English with heavy use of Yiddish words.
• In ancient times the Samaritans were a fairly large sect that split from Judaism and lived in the Holy Land, but had a somewhat different version of the Bible. Jews and Samaritans did not like each other or get along, both seeing themselves as followers of the authentic Mosaic religion and the other as heretics, which lends a lot of important context to Jesus' story of the Good Samaritan (especially since he was preaching to a mostly Jewish audience). Today the Samaritans are seen as a different ethnic group and religion from Jews and Judaism, albeit related to them, and only a few hundred of them are left.
• There have been various men (and one woman) who declared themselves messiah, or were declared as such by their followers. These are universally regarded as heretics outside their followers, since all have failed to live up to the messianic prophecies. The most famous is, of course, Jesus, but other prominent claimants were Shabbatai Tzvi, a 17th-century rabbi who led a popular movement with radical changes up until the Ottoman sultan forced him to convert to Islam or die, and Menachem Mendel Schneerson (died 1994), the seventh and final Rebbe of Chabad-Lubavitch. Schneerson never proclaimed himself the messiah, but some of his followers think he was, and continue to believe He's Just Hiding or will return any day now.

And finally, all three of the Abrahamic religions "tolerate" (or not) each other to various degrees, the only thing they can agree on being their mutual distaste of polytheism. Even that is not consistent, though — Some Christians, like the Portuguese in India, didn't mind trading with Hindus, at a time when said Hindus were largely ruled over by Muslims who rarely made any serious attempts at converting them, and there was a time where Jews didn't mind the existence of other gods so long as theirs was regarded as the top dog and the focus of worship. Historically, Jews have not had major conflict with Hindus. They may see Hinduism as wrong for them, but they don't really care much how other people worship, and Hinduism has no theological basis for antisemitism, something present in both Christianity and Islam.

Other religions

• Pre-Christian example: the 18th-dynasty pharaoh Akhenaten radically and single-handedly overhauled the Egyptian religion from polytheism into sort of a proto-monotheism for reasons that remain unclear to this day. He got away with it at the time because, well, he was the pharaoh, but the religion reverted immediately after he died and Akhenaten got the Un-person treatment from his successors.

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