Derived from the original exclamation Jesus H Christ used where a more aggravated exclamation is necessary to properly describe something. Also plays on the supernaturality of certain situations by hinting on how Jesus walked on water.
Somebody after watching a good moviescene: Jesus H2O Christ that was freakin epic.
you basically grab your nearest metal head that has a beard and long hair and throw them in a rave (specifically at a cosplay convention) Give them a little spike-glowstick crown like Jesus and give something to drink like alcohol and BOOM you got your self a rave Jesus
Guy 1: GUYS LOOK, ITS THE RAVE JESUS!!
everyone: YEAAAAAAAAAAAAAAAAAAAAAAAA
Rave Jesus: *passed out on the floor*