We believe that God sent His only-begotten Son, Jesus Christ, to rescue mankind from the punishment of sin (John 3:16-17). Only Jesus could save mankind because He is both true Man and true God (John 1:14). By His perfect obedience to God’s commands (Romans 5:18) and by His innocent suffering and death, and glorious resurrection from the dead, Jesus paid the debt of sin and won forgiveness, life and salvation for all (John 1:29, 1 John 2:2, Romans 4:25).
The Church teaches that the Word, that is, the Son of God, assumed the human nature in the womb of the Blessed Virgin Mary. So there are two natures – the divine and human – inseparably joined in one person. There is one Christ, true God and true man, who was born of the Virgin Mary, truly suffered, was crucified, died, and was buried. He did this to reconcile the Father to us and to be a sacrifice, not only for original guilt but also for all actual sins of mankind. He also descended into hell, and truly rose again on the third day. Afterward, he ascended into heaven to sit at the right hand of the Father. There He forever reigns and has dominion over all creatures. He sanctifies those who believe in Him, by sending the Holy Spirit into their hearts to rule, comfort and make them alive. He defends them against the devil and the power of sin. The same Christ will openly come again to judge the living and the dead, and so forth, according to the Apostles’ Creed. (Augsburg Confession: Article 3)
I believe that Jesus Christ is true God, begotten of the Father from eternity, and also true man, born of the Virgin Mary; and that He is my Lord, Who has redeemed me, a lost and condemned creature, purchased and won me from all sins, from death, and from the power of the devil; not with gold or silver, but with His holy, precious blood, and with His innocent suffering and death; in order that I might be His own, live under Him in His kingdom, and serve Him in everlasting righteousness, innocence, and blessedness; even as He is risen from the dead, lives and reigns to all eternity. This is most certainly true. (Small Catechism: Explanation of the 2nd Article of the Creed)