If you would like to read a good summary of the doctrine of the Lutheran Church, the best place to start is with the Small Catechism. Here Luther summarizes the principle teachings of the Christian faith. The catechism was written so that fathers could teach their households the basics of the Christian faith, just as Moses commanded the households of Israel to do (see Deuteronomy 6:4ff). 

Here are the basic teachings of the faith which are put forward in the catechism: 

• God has given us His holy law which demands perfect love and obedience. We have sinned against this law and deserve nothing from our Lord but eternal condemnation.
• Despite our sinfulness, God still gives us our bodies, lives, and all that we need. Out of His great love for us, He cares for us even when we are His enemies.
• God's love for us has extended even to sending His only begotten Son, Jesus Christ, to take up our sin and suffer and die to forgive all our sins and give us eternal life and salvation.
• The Holy Spirit creates faith in us by the Word of the Gospel (God's saving word about His love for us in Jesus) so that when we receive salvation it is entirely the gift of God and we are beggars, receiving what God gives with joy but having no part in our own salvation.
• God the Father begets us as His own children, creates faith, and forgives all our sins through the waters of Holy Baptism when the Triune Name (Father, Son, and Holy Spirit) is put upon us with water.
• God has sent pastors into His church to forgive the sins of the penitent. This is as sure and certain in heaven as if God Himself were doing it (because He is!).
• In the Lord's Supper, Jesus gives us His own body to eat and His own blood to drink, forgiving our sins, strengthening our faith, and giving life and salvation.

Learn more about Lutheran Doctrine at these web sites:

• The Lutheran Confessions are a collection of documents written between the second and sixteenth centuries which give a faithful exposition of what is taught in the Holy Scriptures.
• Luther's Small Catechism is a short exposition of the Scriptures which Dr. Martin Luther wrote in order to assist fathers in teaching the Scriptures to their families.
• Luther's Large Catechism was written to teach pastors the same content that is in the Small Catechism.  It is longer and more detailed.  Though it was written for pastors, it is a very helpful confession of faith for any Christian to read.