St. John's believes we are saved by Grace, Faith, and Scripture alone. God through his Grace sent Jesus to give himself to take on our punishment, so that by Faith in him our relationship with God can be restored. All of these things are recorded in Scripture (God's word or the Bible). "I am the way and the truth and the life. No one comes to the Father except through me." (John 4:6)
The LCMS insists that both the Old and New Testament teach both the Law and Gospel. The Old Testament, therefore, is valuable to Christians. Its teachings point forward in time to the Cross of Christ in the same way that the New Testament points backward in time to the cross.