Irish catholic, two friends grow up to become priests but one of them is abused by a priest.

I think both boys are troubled, or grow up in a seminary or something. I vividly remember that the main character’s friend was troubled, and that he was the victim of sexual abuse at the hands of a priest when he was a child. He goes on to horrible things to children, and his friend just watches in horror basically. I can’t remember much more than that, but I do think both characters went on to become priests as well.