Baptism likely originated from earlier ritual practices. Forms of purification by water existed in ancient Judaism, for example, in the mikveh, a "purification bath." During Jesus's time ...

what we might call personal piety among some Jewish groups. This seems to be what's going on in the Essene group. And it may also be what's reflected in the story of John, who practices baptism.

The Jewish and Protestant religious authorities ... against the practice in some of the institutions of forcing Catholic baptism on non-Catholics believed to be at the point of death.