Much of the episode takes place in a church and its grounds, including a crypt in the basement. The central interest of the episode is the two characters' discussions about belief in God. Dean, the older brother is a believer in demons and vampires but not in angels and God. He represents an aggressive atheism. Sam disagrees strongly:
Dean: Look, I'll admit I'm a bit of a skeptic, but since when are you all "Mr. 700 Club"? No, seriously, from the git-go you've been willing to buy this "angel" crap. I mean, what's next? Are you going to start praying every day?
Sam: I do.
Dean (shocked): What?
Sam: I do pray every day. I have for a long time.
Dean (face shows disbelief, then grudging acceptance): The things you learn about a guy. . . .
Dean states explicitly and indeed dogmatically that there is no God and no meaning in the world. He says that he requires hard proof that there is God, although he doesn't need any hard proof that God doesn't exist.
Later in the episode, Sam sees the angel himself. Dean is skeptical, of course, and asks for details. After describing what he saw and heard, Sam says, "This feeling washed over me, like peace, like grace."
Sam says that he has been given an assignment to kill an as-yet-unknown evildoer, and he soon encounters the target. Dean intervenes and says that he'll do the job himself, leaving Sam behind.Sam is no fool, however, and determines that the "angel" is in fact the ghost of a former priest in the parish. A bit of interesting, offbeat theological discussion between Sam and a priest follows, and the ghost is put to rest by a performance of the Catholic Last Rites.
Dean, meanwhile, has gone after the person Sam was told to kill. It turns out that the person was about to commit a rape, which Dean intervenes to prevent. The man tries to escape, and in the ensuing automobile chase he is killed in a distinctively unusual accident, impaled by a metal post. Surveying the scene, Dean looks on in evident wonder.
Afterward, Sam and Dean discuss the implacations of the events. Sam confesses that he was fooled by the ghost: "I just wanted to believe so badly. It's so damn hard to do this, what we do, all alone. There's so much evil in the world, I feel like I could drown in it. . . . I needed to think that there was something else watching, too, you know? Some higher power, some greater good, and that maybe . . . I could be saved."
Dean sympathizes and acknowledges that the events of the episode were so extraordinary as to shake his beliefs.
Dean: "I don't know what to call it."
Sam: "What? Dean, what did you see?"
Dean: "Maybe . . . God's will."
From Karnick on Culture.