The author is giving us the good news of Jesus Christ. But he straight away goes to the Old Testament to speak about his messenger and his arrival. The story has something to do with the Old Testament. In fact the story is the fulfilment of the Old Testament sayings and prophecies. The story of Jesus is nothing but the fulfilment of the prophets and Moses. All what the author was going to say was nothing but fulfilment of the Old Testament.
Quotations are borrowed from two prophecies–that of Isaiah and that of Malachi. Both of them spoke of the beginning of the gospel of Jesus Christ. Malachi says that the messenger is sent to prepare the way of the Lord. Prophet Isaiah says that John the Baptist is the voice that cries in the desert. His dress and his food reveal that he was not conforming to this world. His way shows that we have to live above the world and worldly things to prepare the way of the Lord.
John the Baptist preached a baptism for the forgiveness of sin. This was the command which Jesus gave his disciples after resurrection. So Jesus’ story begins and ends with the baptism for the forgiveness of sin. The great promise Christ makes in his gospel to those who have repented, and have had their sins forgiven them is that they shall be baptized with the Holy Spirit.
