How we cite our quotes: In consultation with my editor, we decided (against standard practice) to go with page numbers—since The Sunset Limited is one long act and it would be unwieldy and impractical to number all the lines.
Quote #4
BLACK: I see a different truth. Settin right cross the table from me.
WHITE: Which is?
BLACK: That you must love your brother or die. (121)
Black indicates that the only alternative to loving your fellow human is death—maybe not literal death (though that's where White's headed), but spiritual death, or being dead on the inside.
Quote #5
WHITE: Well, the trick bag seems to have shaped itself into some sort of communal misery wherein one finds salvation by consorting among the loathsome. (128)
White claims that Black's vision of brotherly love is really just a shared misery; it's not consoling. Since he sees the junkies Black helps as being entirely "loathsome"—as opposed to people with good and bad in them—he doesn't see any point in aiding them. Misery seems to spread like an infection to White.
Quote #6
WHITE: […] You say that I want God's love. I dont. Perhaps I want forgiveness, but there is no one to ask it of. (141)
Earlier, Black suggests that human beings act like they want any number of different things, when what they really want is God's love—they're just hiding from it. White flat-out denies this… but he admits he wants forgiveness. Why? What's bothering him? Not going to see his dying father? Or is it something else, something unknown?