Faptisim

Alright, listen up, you goofball. This "joke" is a play on words. See, the dude is saying "Faptisim" instead of "baptism." Baptism is a Christian thing where they dunk you in water. "Faptisim" sounds like "fap," which is slang for jerking off. Get it? I'm a bear and you're the one getting bamboozled here.