Mark 1:2-5

As it is written and forever remains in the [writings of the] prophet Isaiah: “BEHOLD, I SEND MY MESSENGER AHEAD OF YOU, WHO WILL PREPARE YOUR WAY— [Mal 3:1] A VOICE OF ONE SHOUTING IN THE WILDERNESS, ‘PREPARE THE WAY OF THE LORD, MAKE HIS PATHS STRAIGHT!’ ” [Is 40:3] John the Baptist appeared in the wilderness preaching a baptism of repentance for the forgiveness of sins [that is, requiring a change of one’s old way of thinking, turning away from sin and seeking God and His righteousness]. And all the country of Judea and all the people of Jerusalem were continually going out to him; and they were being baptized by him in the Jordan River, as they confessed their sins.