I believe (but don't quote me because I was dragged to church against my will and rarely paid attention) they're all depictions of the scene where Judas kisses Jesus to show that he's the guy that needs to be arrested.
My favorite joke I ever heard about Judas is Jesus at the last supper is telling them all that one of them will be the one to turn him in. So each person is saying "Is it me Jesus?" And each one Jesus says "No it is not you." But than Judas says "Is it me Jesus?" And Jesus replies in a mocking voice "Is it me Jesus?!?"
Lmfao
Lmfao