The original act of baptism was originally a Jewish practice!
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.