John said to the priest and Levites who questioned who he was, 'I am the voice of the one calling in the desert, Make straight the way for the Lord.' John1:23.

John preach the gospel and taught the people the good news about Jesus and he baptised them in water, this was his preparation for people to receive Jesus. He told them Jesus will baptise with the Holy Spirit and He (Jesus) is more powerful than him.

John introduced Jesus as the 'Lamb of God' because God who sent him to baptise with water told him he was to make the way for one who will baptise with the Holy Spirit, one whom he (John) is not worthy to stand in his place.

John testify that the one who sent him gave him a sign, that the Spirit would come down as a dove and remain on the one who would baptise with the Holy Spirit. He will know He is the Son of God.

Jesus is the Lamb of God, he came to wash away our sins, He came to die for us.