In Jesus, God the Son became a human being. It is called 'the incarnation' because God became visible 'in the flesh' in the person of Jesus of Nazareth. The most usual way Christians express this belief is by calling Jesus the 'Son of God'. This connects to the doctrine of the Trinity, where the term 'Son' is used to name the second person of the Trinity. When Christians call Jesus the 'Son of God' they mean that he is God who has become a human being; that he is the 'incarnate Son'. Christians also believe that Jesus is 'fully God and fully human'. Christian believe that Jesus is one person, with two natures: one human nature, and one divine (which means 'godly') nature.In the kenosis hymn in Philippians St. Paul shows how Jesus 'emptied himself' of his divine nature to become human. Source of Authority - In the beginning was the Word, and the Word was with God, and the Word was God. He was with God in the beginning. Through him all things were made; without him nothing was made that has been made... The Word became flesh and made his dwelling among us. We have seen his glory, the glory of the one and only Son, who came from the Father, full of grace and truth. (John 1:1-3,14)