He never said a word about debasing Christians only after they when after his sacred cow...er, spaceship, whaterver.
Nor did he mind the mormon episode, which I think trashed the mormon faith more than anything they've done about christians.
When they first did the episode, I remember us all discussing whether Isaac would quit. We noted he wasn't on the episode, and frankly I can't remember if he's been on one since that episode, which was one of their funnier episodes, especially how the credits at the end everybody was John smith or Jane smith.