Levi had already assumed that Chris is Catholic based purely on the fact that he's from Bahhhston. But that doesn't matter. He's a Jewish boy now.
"Just be your new roommate, but more Jewish," he jests without thinking, then pauses to reconsider, "Shit, is that a bullying statement? How am I going to unlearn my Problematic Behavior? This is why we need our youth group."

Youth group is probably just going to turn into scheduled times to hang out together in the woods and smoke weed, but whatever.