Only he preached to the people that they needed to be ready to recognize Jesus as the Son of God when He came. By asking forgiveness for their past sins and getting their hearts right with God. Yes, except the people that John was preaching about had broken their covenant with God as a nation. They had not followed His commandments and had to be punished time and again for their sins. So, the Israelites had forgotten their promise to God, and had to be punished.
Redemption forgives the past and offers a way to keep from repeating the same sins again.
By coming into the world in the person of Jesus Christ, God gave us additional spiritual guidelines for living, and for behaving towards each other more compassionately. So the child grew and became strong in spirit, and was in the desert until the day of his manifestation to Israel. Shouldn't I be asking God to prepare my heart for Christmas. As Zacharias explained, John was to go forth and prepare the way for the arrival Of Jesus, God's own Presence. When Jesus arrived He would show us how we could survive the threats of godless people.