Other than Don Epps (played by Rob Morrow) who is Jewish (and the Epps are supposedly Jewish), no other character on the show has any specific belief system or subscribes to one. Larry Fleinhardt (played by Nichols) stayed in a Buddhist monastery but is not Buddhist though he does seem to be on the search for something greater than himself. The only “Christians” that have been on the show were cults (Apostolic Saints who were modeled a little after the FDLS and Warren Jeffs) and another group where they believed in some out there conspiracies but the “leader” was fleecing the congregation (I think but it’s been awhile). Now, that doesn’t mean that they are anti-Christian but rather that cults sell views. Though they did, in at least the conspiracy cult group ep, point out that they shouldn’t twist a belief in a higher power to control people or use that belief in evil ways. They tended to stick to behavior and actions rather than beliefs except if they got people killed.
I like the show because they don’t end every ep with a gun fight or killing people. I know a fair percentage of last season’s eps (Season 5) ended up with an arrest instead of a shoot out. And it’s not like CSI which focuses on the procedural but on characters and their development.