The Christians invite the two men for dinner and a discussion of religion ensues. The Christian man assumes both guests are gay and mentions the abominable nature of homosexuality re the Bible. The straight guy is an atheist who gets mad.
(This isn't in chronological order; I'm just remembering the highlights.)
In his subsequent tirades he focuses on the evil/tragic in the world as proof God does not exist. The Christian doesn't really have an answer.
(At which point I would have gone to the window, looked out, and said, "You know, there is a lot of tragedy in the world, but all I'm seeing is beauty. The love of a good woman. Good health. Freedom. Food, etc. There's more evidence of a loving God than not.")
Anyway, the straight guy decides to teach the Christian man a lesson by seducing his wife. In the course of the seduction he goes on more tirades of how homosexuals are mistreated, the Bible flawed, etc. It really was unending.
The Christian man goes psycho. He ties up his wife and tells the atheist that either the atheist commits suicide by jumping off "The Ledge" or the woman dies.
That's where Terrence Howard comes in as the detective who tries to talk the guy out of jumping.
Meanwhile, Terrence Howard is going through his own tragedy where his wife had sex with his brother to have children that looked like Terrence. Terrence just found this out and confides all of this to the jumper. The jumper tells him to forgive and forget and go home.
The jumper jumps. The Christian husband is arrested. And in the end the only people who were decent were the fags and the whore.
BTW, Terrence Howard went home and sat down to dinner with his family. The son wanted to say grace. Howard said no. No grace tonight. The implication was that the atheist converted Terrence.
I've never seen such an amateurish hit piece on God and the Bible. They wouldn't have been any more obvious if the whole movie had just had the words, "Christians bad; fags good."