Mark 1:2-4

Just as it is written in the prophet Isaiah: Behold, I send My messenger before Your face, who will make ready Your way–[Mal. 3:1.] A voice of one crying in the wilderness [shouting in the desert], Prepare the way of the Lord, make His beaten tracks straight (level and passable)! [Isa. 40:3.] John the Baptist appeared in the wilderness (desert), preaching a baptism [obligating] repentance (a change of one's mind for the better, heartily amending one's ways, with abhorrence of his past sins) in order to obtain forgiveness of and release from sins.