There are two aspects to the Incarnation, one identifies the action of God becoming man (first sentence) and the second is the reality of Jesus being God and man (second sentence). The Incarnation refers to both facts. The reason for the Incarnation is to save humanity which is expressed in the first sentence. It is important to realize that God the Son has always been the Son and is eternally the Son. Jesus as a human being who is God only came into existence when his humanity was united to his divinity. But we generally talk of Jesus always existing since He has always existed as a divine person. Just as the Son is eternally begotten of the Father, so the Father gives Jesus to humanity to save humanity, love humanity and share his divine nature with humanity.