"Among those born of women there has been none greater than John the Baptist; yet the least in the Kingdom of Heaven is greater than he" (Matt 11:12).
John the Baptist was the last and greatest of the prophets of the first Covenant. His mission was to hold people accountable to the Law. His message to the people on the banks of the Jordan was to repent of their sins and make amends for any harm or neglect done to others. He was a commanding presence and his voice was filled with warning for the coming of God's judgment.
Jesus calls him the greatest person who ever lived up to that moment. But something new was happening. The dispensation of the Law was being surpassed by God's infinite, undeserved gift of mercy, poured out on anyone who turned toward God to receive it. The reign of God opened the doors of salvation to everyone, and Jesus says that the poor, the undeserving, the unrighteous and the masses who were ritually unclean and incapable of observing all the tenets of the Law were the first to respond. They had heard his preaching and believed in the gracious welcome God was extending to sinners, and they were taking heaven by storm.
So despite John the Baptist's undisputed greatness under the Law, even the least who heard and responded to God's free offer of acceptance and forgiveness was greater than John. The Love of God was greater than the Law that had ruled and guided the chosen people since Moses.
In Jesus, the intimate, compassionate heart of God was revealed, especially to the poor and to sinners. John had proclaimed the coming of the Messiah, a figure of awesome power, sent to pass judgment. What even John did not recognize until the end of his life, facing martyrdom in Herod's prison, was that Jesus was in fact the Messiah, but not come to judge and punish, rather to forgive and heal God's people, broken under the burden of human sin and the condemnation of the Law.
Jesus again proclaims God's compassion by his coming in this season of expectation of repentance. Advent is our time to storm heaven. Christmas is our time to receive God in human vulnerability and humility, filled with compassion, opening the heart of God to all, especially sinners.
This is the joy of the Gospel.