I was wondering if the act of baptism was originally a Jewish practice? If not, then how did they know what to do when they were told that after accepting Christ, they needed to be baptized? Did they understand why they needed to be baptized? Also, if baptism was originally a Jewish practice, what were they being baptized for – or into?
Baptism comes from the Greek word baptisma that means ritual washing. It originated in the Jewish mikvah, also a ritual washing.
Both are meant to symbolize purification. Some Jewish men take a mikvah every Friday in preparation for the weekly Sabbath and before every holy day. It’s also done before one’s wedding or the circumcision of a son, or at the beginning of a great undertaking on the Lord’s behalf. Jewish women take a mikvah each month after their menstrual period.
All converts to Judaism take a mikvah upon entering the faith. So like the mikvah, a baptism symbolizes purification. But unlike the mikvah, one baptism lasts a lifetime.