Studies in comparative religion focus on the similarities of different religions. It is fascinating to note the way religions overlap. For instance, the dietary laws of Jews and Muslims (kosher and halal) or the similarity between immersing in a mikveh and the act of baptism.

For some people, the fact that certain rituals appear to overlap can be a reason for skepticism, but it need not be. This ancient question was actually captured by the sages in a fascinating Midrash:

“An idolater asked Rabbi Yochanan ben Zakkai: ‘These rites that you perform look like a kind of witchcraft. You bring a heifer, burn it, pound it, and take its ashes. If one of you is defiled by a dead body you sprinkle upon him two or three drops and you say to him: You are clean!’ Rabbi Yochanan asked him: ‘…Have you ever seen a man possessed by this demon of madness?…And what do you do in such a case?’ ‘We bring roots and make them smoke under him, then we sprinkle water upon the demon and it flees.’ Said Rabbi Yochanan: ‘Let your ears hear what you utter with your mouth! Precisely so is this spirit a spirit of uncleanness…Water of purification is sprinkled upon the unclean and the spirit flees.’

When the idolater had gone, Rabbi Yochanan’s disciples said to their master: ‘Master! You put off this man with a mere makeshift, but what explanation will you give to us?’ Said he to them: ‘By your life! It is not the dead that defiles, nor the water that purifies! The Holy One, blessed be He, merely says: I have laid down a statute, I have issued a decree. You are not allowed to transgress My decree; as it is written (Numbers 19:2), This is the statute of the law’” (Numbers Rabbah 18:20).