Earn Your Happy Ending: Subverted in Romans 11:6 in regards to doing good deeds to go to Heaven. No matter how hard a person works, they can't earn their way up there, but because Jesus died for humanity's sins, all we have to do is to accept Him as our savior to make it up to Heaven.
God is Good: Many of the verses focus on God's love and He will forgive us if we repent.
Good Needs Evil: Romans 6:1-2 defies this against people who use this as an excuse to do things that they know are sinful.
"What shall we say then? Shall we continue in sin, that grace may abound? God forbid. How shall we, that are dead to sin, live any longer therein?"
Hard Work Hardly Works: Paul deconstructs the idea that it's possible to earn your way into God's grace with good works rather than faith. Imperfect people can't keep the perfect Law, and anyway God's grace is a gift and gifts can't be earned.
Holier Than Thou: Deconstructed in the beginning of Chapter 2, when, after listing several obvious sins in the previous chapter, Paul continues by pointing out that if you're inclined to judge those sinners, that shows you're just as guilty.
Humans Are Flawed: Many verses focus a lot on this, most commonly Romans 3:23 - "For all have sinned and fall short of the glory of God.".
Hypocrite: The Jews in the second book in which Paul calls them out on it.
Know-Nothing Know-It-All: Paul describes NayTheists this way, since they know God exists but reject Him for idols as a pretext for immorality. "Professing to be wise, they became fools."
"Being filled with all unrighteousness, fornication, wickedness, covetousness, maliciousness; full of envy, murder, debate, deceit, malignity; whisperers, backbiters, haters of God, despiteful, proud, boasters, inventors of evil things, disobedient to parents, without understanding, covenantbreakers, without natural affection, implacable, unmerciful..."
Misery Builds Character: Discussed in Romans 5:3-5 where Paul notes that suffering builds endurance, endurance builds character, and character builds hope. Considering the time period, he and many of the other Christians that were physically tortured and martyred for their faith knew what they were talking about from many experiences they could count by the lashes on their backs.
Nay-Theist: Paul accuses the atheists of really being this in the first chapter, which declares that the existence of God is entirely evident and undeniable.
Terror Hero: Those in high authority ordained by God are described as this in Romans 13:3-4 as it concerns to keep its subjects from doing evil.
"For rulers are not a terror to good works, but to the evil. Wilt thou then not be afraid of the power? Do that which is good, and thou shalt have praise of the same: For he is the minister of God to thee for good. But if thou do that which is evil, be afraid; for he beareth not the sword in vain: for he is the minister of God, a revenger to execute wrath upon him that doeth evil."
Turn the Other Cheek: Romans 12:17-21 implies this. However, even though we have to forgive our enemies, it's only God Himself who will repay them back.
Viewers Are Geniuses: Scholars have observed that this is the only New Testament epistle that seems to be constructed specifically as a theological treatise, rather than a personal letter about specific concerns in the Early Church. Theological commentaries on it can run to multiple volumes. This is amusingly referenced in The Bible itself, when Peter remarks on Paul's letters in one of his own epistles: "His letters contain some things that are hard to understand..." (2 Peter 3:16).