The Baptism of Jesus
This is the passage where Jesus is baptised and then the Spirit of God descended on him in the form of a dove. God then speaks and announces that Jesus is his son - so if John the Baptist wasn't enough to convince you hopefully the voice of God speaking from the sky is . A point of interest is that in John, John the Baptist says that he didn't know that Jesus was the one until the dove came. Remember they were "cousins", and probably knew each other reasonably well. God had independently sent John out to do His work, and so John must have found it slightly amusing that all this time he had known the saviour of the world, without knowing that he was the saviour of the world!