The teaching of every church can be grouped under two headings: source and content. The source of teaching is the church’s authority, what voice is heard in the church. The content of a church’s teaching is what it believes, teaches and confesses. This introduction will briefly discuss the source and content of Lutheran teaching.
The only voice that is heard in the church is the voice of the Holy Trinity. This voice is heard in the writings of God’s chosen instruments, the prophets and apostles, therefore the only source of the church’s teaching is the Holy Scriptures, the prophetic and apostolic Word of the Lord. As King David prayed, “Your Word is a lamp unto my feet and a light unto my path.” [Psalm 119:105] This teaching of the unique authority of the Scriptures is called “Sola Scriptura, Scripture Alone.”
The Scriptures are inspired. “All Scripture is given by inspiration of God.” [1 Timothy 3:16] The Scriptures are inerrant (without error). “The Scriptures cannot be broken.” [St John 10:35] The Scripture are infallible (unable to err). “It is impossible for God to lie.” [Hebrews 6:18] Most importantly, the Scriptures contain the promise of the Gospel, that is, the promise of the forgiveness of sins. The Gospel is the “means of grace,” that is, it is the only instrument that the Holy Spirit uses to create and sustain saving faith. “I am not ashamed of the Gospel, for it is the power of God unto salvation to all who believe.” [Romans 1:16, see also St John 17:17,20; Acts 11:16; Romans 10:17; 1 Corinthians 1:21]
Under the Scriptures sit the symbols of the church: the Creeds and Confessions. In these symbols the church rightly confesses the teaching of the Scriptures. The Creeds and Confessions are not a source of teaching, rather they faithfully confess the Scriptures and reject those errors that are contradicted by the Scriptures. The Confessions of the church are contained in the Book of Concord (published 1580).
The chief content of the church’s teaching is the Gospel, which is the promise of the forgiveness of sins won for all sinners through Jesus’ death on the cross. The prophets (the Old Testament) and the apostle’s (the New Testament) all testify of the salvation that comes through faith in Christ. “To Him [Jesus] all the prophets give witness, that through His name who ever believes in Him shall receive remission of sins.” [Acts 10:43] St Paul says, “For I determined to know nothing among you save Christ crucified.” [1 Corinthians 2:2] So the Lutheran church has always taught and confessed that the chief article of the Christian faith is justification by grace alone through faith alone.
This, of course, does not mean that there are no other teachings in the Scriptures, or that teachings in the Scripture that are not the Gospel are not to be heard. God speaks to us in the Law (what we are to do to be holy before God, and what we fail to do) and the Gospel (what God has done for us in Jesus to save us). Both the word of Law and the word of Gospel are heard in the church. We do not reduce the teaching of the Scriptures, but delight to hear all of the Lord’s words. As the Lord spoke before His ascension to the right hand of God, “teach them to obey everything that I have commanded you, and lo, I am with you always to the end of the age.” [St Matthew 28:20] It is our hearing and keeping (treasuring) of the Lord’s Word that marks us as His people. Again, as the Lord taught, “My sheep hear My voice, and I know them, and they follow Me.” [St John 10:27]