John came proclaiming a baptism of repentance for the forgiveness of sins, but John himself attested that one who was "mightier than I" was coming to baptize them with the Holy Spirit. It's one thing to turn AWAY from sin, but to turn TO the One who conquers evil and fills us with the Spirit of God Himself?! This is something else! The Gospel of Mark introduces us to King Jesus, the greater one, the one who is mightier than I, the one who we've all been waiting for.