Good-bye to The Unit

David Mamet's series "The Unit" has finally left TV after about a five year run. I have been catching up on the whole past year on library checked out DVDs, as my spouse loves The Unit. I like it, but keep expecting Dennis Haysbert to stop and sell Allstate Insurance in the middle of a fire-fight with enemy terrorists.
One thing that cropped up frequently in the final season were religious references. It is interesting that a career soaked in violence would also be familiar with the Bible and religious traditions? Is Mamet just offering interesting characters or is he saying something about the close tie in America between a heritage of violence as well as a national reputation of being decidedly a country of faith?