John the Baptist called his followers to repent and believe the Good News. Those who came to him and were baptized by him accepted his teaching and his teaching was that he was baptizing them in water as an introduction to the One to come. His baptism has no power to save but the One who was to come had the power to give salvation through the sacrament of baptism. John publicly declared that he was not the One awaited but only preparing for the One who was to come; who was, as yet manifested, but who was much more powerful than John. The One who was to come would baptize with the power of the Spirit and with the blessings of Heavenly Fire.
Those who accepted the teaching of John the Baptist, accepted also what he said about the One who was to come. John called for repentance and the readiness to welcome the One who was to come- Jesus- and when Jesus came he called us to believe in God the Father who had sent him to reveal God's love for us. He came to live amongst us to give us salvation and eternal life.
John was sent to prepare the way for the Lord and called us to believe the Good News. His teaching made people think that John was the Messiah but he denied saying he was not the Messiah but only preparing for the Messiah who was to come. John the visible messenger of God would open our eyes and mind to welcome the invisible One to come.
Jesus, the only Son of God was sinless and needed no baptism but he came to John for the baptism in order to testify to the validity of the baptism John gave. John refused to baptise Jesus for two reasons. Firstly, John believed that Jesus, the Sinless One, had no need of baptism at all and secondly John felt himself unworthy of baptizing him. However, Jesus insisted that John baptize him. John probably had no idea that after receiving the baptism the Heavens would open and a Voice would call people to listen to Jesus. The voice was telling that Jesus is divine, the only Son of God, who came to live amongst us and to save us. The Voice and the presence of the dove were signs from 'on high' to testify to the divinity of Jesus. It also confirmed that what John had said about Jesus was correct and true in every aspect and that those who believed in him would be baptized with the Spirit and with Fire. Those baptized with Spirit and Fire would become heirs of the kingdom. Through baptism we become sons and daughters of God and become a member of God's universal family on earth and in heaven.
The baptism Jesus received affirmed that his teaching about God's love and salvation for mankind came from God. Secondly, the voice from on high affirms the unity between God the Father in his words and deeds. To know and believe in Jesus is to know the Father and to listen to Jesus is to listen to the Father. God is not visible to us but we know God through the teachings of Jesus.