In other words, immersion in water is only the beginning of true baptism. His baptism into death, begun at Jordan, was now completed. He now begins a new life completely dedicated to the Lord. This would be impossible to do on one's own, but Jesus' sacrifice and resurrection have guaranteed that all the help needed will be there. Baptism into death is the real baptism for the church, as it was for our Lord.
Water baptism is only a symbol, or picture of it.
Those who have willing, honest and teachable hearts will strive to follow in the footsteps of Jesus the rest of their lives. If they remain faithful in doing this they will share with him in the first resurrection.