Ambiguous Ending: Most episodes imply that once the angels have done their work, that assignment is finished. However, some episodes seem to leave loose ends. Sometimes, future episodes clear these up (ex.: Season 2's "The Feather" was an extension of "Fear Not," the Christmas episode from Season 1). But some are left hanging. For example:
Did Carla Robinson have to return to prison after realizing her guilt in "True Confessions", even though the court had formally declared her innocent?
In season 4's "Baking Bread", he sows racial hatred in a small town, resulting in the death of a young black man.
In season 7's "Netherlands," he attempted to corrupt a weakened Monica after a terrorist bombing killed dozens of people.
In the series finale, he causes an explosion within a school, killing dozens of children and several teachers. He then accuses an innocent man named Zack (really God in disguise) of being the culprit. Arrogant and prideful, Satan desired nothing less but to destroy everything that God valued out of petty spite.
Glurge: Sending the message of God's love mixed with feel good sentimentality and sugary Glurge ain't exactly a good idea.
Monica's crisis of faith and temptation by Satan in "Netherlands" is the direct result of her witnessing a building being destroyed by a bomb, killing many. It aired May 6, 2001, and a repeat had to be pulled from CBS's schedule in the wake of 9/11 later that year.
John Dye, who played Andrew — an angel of death — from the second season onward, died in January 2011 of a heart attack. Out of the four main protagonists, he was the first to go.note And, ironically enough, the youngest cast member of the quartet.
The first season of the show had an angel of death named Adam as a recurring character. He was played by Charles Rocket, who committed suicide in 2005.
Season 3 had an episode "Sins of the Father," where a character played by Robert Ri'Chard has, and takes, the chance to walk away from gang life after being tempted to kill a man. Four seasons later, Ri'Chard would star in an episode where his character kills a former mentor and is sent to prison for at least 25 years.
The 1998 episode, "The Trigger", features a family torn apart when a woman's sister kills the former's abusive husband and every member, including the couple's young son, display a wide array of emotions (the boy felt a great deal of anger over his Dad's death and hatred towards his mother and is last seen in the episode walking off-screen, still angry and surprisingly this was not resolved by the episode's end). Eight years after the episode aired, the actor who played the boy, Joseph Pichler, went missing and has yet to be found.
One episode involved a woman trying to pass the physical trials for the military, and struggling with climbing a certain wall. The sarge in charge tells her she doesn't have to climb it, after failing to drive her off. At the last second, she realizes it's a trick and then climbs it anyway. As of 2015, women in the US military still have much lower physical standards than men.
Nightmare Fuel: A surprising amount of it. "The Man Upstairs", "Into the Light", and "The Occupant" come to mind.
Gregory, just Gregory. Unlike the shows fairly tame portrayal of Satan he was like a demon from a horror movie complete with demonic growls as he was exorcised.
"Redeeming Love" from season four has some of this. The episode involves Monica helping a crack addict named Lydia, and viewers are spared nothing when it comes to the withdrawal process. In-universe, Lydia has some nightmares of her own, one involving a giant spider.
Any episode involving explosions, guns, or other violence can be this depending on the seriousness of the situation. The same is true for episodes involving mass or graphic death. Season two's "Dear God," involving the Holocaust, and season four's "The Spirit of Liberty Moon," involving the persecution of Chinese dissidents, get special mention.
"Black Like Monica" has Monica transformed into a Black woman to understand the struggle they go through. She then finds herself at the mercy of two Klansmen who are pursuing her with the intent of killing her. At one point, she is crouched behind a tree with both of them hot on her trail, crying and begging God to turn her back into a White woman. He does just in the nick of time as they find her.
In the aforementioned "Netherlands" episode, after seeing a young girl and her mother walk into a building, Monica, Tess and Gloria watch as Andrew heads into the building, but not before he makes eye contact with the women and is clearly sad about what is about to occur. Then Gloria, who was told by her mentors what his title was, asks how many Angels of Death does is take to complete a job. They then notice that there are dozens of them going into the building. Whereas Gloria is still unaware of the gravity of the situation, Monica and Tess are horrified at this scene and know exactly what is going to happen only seconds before the building explodes.
At the conclusion of "Into The Fire", as Monica has failed to convince the cult leader to come with her, she and Andrew exchange a sad look and Andrew shakes his head before resting his hand on the man's shoulder. It's one of many moments where we see that Andrew's job is often a sad one and that he doesn't enjoy it.
The November 20, 2017 death of Della Reese, who played Tess.
As mentioned under Harsher in Hindsight, the 2011 passing of John Dye (Andrew). He was the youngest main cast member, and the first to have died (this was six years before Reese's passing).
What an Idiot!: You DID have to feel bad for the victim (as well as his parents) in the episode "The Peacemaker", but at the same time, you realize he was also this in the end. A teenage boy with a troubled past involving drug abuse is graduating from high school and is also dealing with his parents' failing marriage. So, the kid one day is in a bank when it is robbed at gunpoint. One of the robbers tells him to give him the money (which even Andrew urges the boy to do so that he would not be needed), but he refuses, saying that he needs it for an important reason. He is shot because of this and dies. So while the parents are blaming each other and themselves for his death and fearful he needed the money to buy drugs, Andrew and an independent filmmaker come to them one night and gives them what he needed the money for; to pay him off for a tape made for them to remind them of him as he's away at college and fonder memories of them in an attempt to stay together. It worked. However, you have to wonder why he gave up his life just to keep his folks together when he could have gotten the money some other way (maybe through the Angels' help, perhaps?), gave them the tape and live.
The Woobie: At least half the characters on the show.
Andrew got a couple of moments, like in "'Til Death Do Us Part," when he seriously thought he'd failed an assignment.
Even Tess got at least one, her bout with Alzheimer's disease being the biggest.