“The whole Judean countryside and all the people of Jerusalem were flocking to him, and they were baptized by him in the Jordan River as they confessed their sins.” (Mark 1:5)
Around A.D. 30 a Jewish rabbi came out of the Judean wilderness, dressed a little like the Geico caveman, to call on fellow Jews to come to the Jordan River, repent from their sins against YHWH and be baptized. In fact, later, Jesus himself would come to be baptized by John.

