I've often slagged players and coaches for being "religious nuts" - Tony Dungy for singling out Lovie Smith as a Christian coach in the Super Bowl, or Jon Kitna for asserting that the Lord allowed him to play despite a concussion. But that Andy Pettitte was driven to take responsibility for his HGH use and confirm that Brian McNamee was telling the truth (as least with respect to Pettitte) largely on the basis of his religious faith is refreshing. Instead of seeing religion as a reason to exclude or moralize or fantasize, Pettitte saw it as a basis for doing the honorable thing - telling the truth and coming clean even though it was a difficult choice.
I'm sure everyone has their own views on religion, but for me, this should be the reason anyone would be religious - to act as a foundation for moral and just behavior.
As a Yankee fan, I always liked Pettitte - his enormous 1-0 Game 5 win over John Smoltz in the 1996 World Series (that I watched on broadcast TV in a motel in Missouri while I was driving to California from New York by myself) was one of the best baseball games I've ever seen. And I think the way he acquitted himself over the last week or so only reinforces that.