I'm always fascinated by how religion informs the decisions of fictional characters. Sometimes this is blatant, with a character that is defined by being raised within a certain belief system (Matt Murdock and Catholic guilt, the irony of him dressing up as a devil). On other occasions, a character's religious background is more subtle or only hinted at, which allows for speculation.
For instance, in The Avengers Captain America's line about "there's only one God ma'am, and He doesn't look like that" was perfect for a boyscout out of the 1940s. I'm imagining Steve as a Methodist, as he's relatively hopeful and forgiving but has a stern system of absolutes and respect for authority.
John McClane has a great line in the first Die Hard: "Sister Teresa called me Mr. McClane in the third grade. My friends call me John, and you're neither, shit-head." I picture John as a bit of a lapsed (Irish) Catholic, with a very Old Testament ideal of the world that plays into his hardened New York cop personality.
In The Raid, morning prayers is shown to be an important part of Rama's pre-dawn routine, but being a Muslim has little to do with the plot. Nice character beat that, perhaps, says a lot about his empathy for both civilians and his wayward brother.
So what other movies handle religion in subtle ways that invite the audience to interpret characters' actions through that lens?