The Holy Bible is the final authority in all matters of faith and practice for Reformation Christians. The Augsburg Confession is the doctrinal confession of faith adopted by the Lutheran Church. It is part of the Book of Concord, which includes the three ancient ecumenical creeds: the Apostles’ Creed, the Nicene Creed, and the Athanasian Creed. It also contains the Apology of the Augsburg Confession, the Smalcald Articles, the Treatise on the Power and Primacy of the Pope, Luther’s Small and Large Catechisms, and the Formula of Concord. (reference)
Martin Luther wrote the Catechisms and the Smalcald Articles. Phillip Melanchthon wrote the Augsburg Confession, its Apology, and the Treatise. So, Melanchthon wrote more of the Lutheran doctrines than Martin Luther. Note that the other writings of Luther have no official status among Lutherans, although most of them make for sound reading.
The Augsburg Confession was written in a particular historical context in which the Lutheran movement attempted to explain and justify itself to the religious and civil authorities of the day, notably Emperor Charles V of the Holy Roman Empire, at the Diet of Augsburg on June 25, 1530. Although reconciliation did not happen, the Augsburg Confession provided the primary confession of the Lutheran movement.
The twenty-eight articles in the Augsburg Confession consist of twenty-one statements of doctrine and seven declarations about abuses, and demands for reforms. Although Melanchthon and his associates compiled the confession, Luther approved it as an accurate account of his doctrine.
A brief summary of each Article, Title, and Description are as follows:
We believe, teach and confess –
I God: affirms there is one divine essence who is called and is truly God, and three persons in this one divine essence, equal in power and alike eternal: God the Father, God the Son, and God the Holy Spirit.
II Original Sin: affirms that since the fall of Adam all those born according to the course of nature are conceived and born in sin, and cannot be justified before God by their own strength and reason.
III The Son of God: affirms the incarnation, that Jesus Christ is fully human and fully divine. He alone brings about the reconciliation of humanity with God.
IV Justification By Faith: affirms that people cannot be justified before God through their own abilities but must wholly rely on Jesus Christ for reconciliation with God.
V The Office of Preaching: affirms that Christ established the office of the holy ministry to ensure that the gospel of Jesus Christ is proclaimed throughout the world.
VI Of The New Obedience: affirms that the good deeds of Christians are the fruits of faith and salvation, not a price paid for them.
VII Of The Church: affirms that there is one holy Christian church, and it is found wherever the gospel is preached in its truth and purity and the sacraments are administered according to the gospel.
VIII What The Church Is: affirms that the Word and the Sacraments are always valid despite the failings of those who administer them because these Sacraments are instituted by Christ.
IX Of Baptism: affirms the necessity of Baptism, and that through it is offered the grace of God, including for children (with their parents’ permission and promise to raise them in the faith).
X Of the Lord’s Supper: affirms that the bread and wine distributed and received in the Holy Supper are truly the body and blood of Christ.
XI Of Confession: affirms that private absolution should remain in the church, though a believer does not need to enumerate all of his sins as this is impossible.
XII Of Repentance: all those who sin after their Baptism receive forgiveness of sin whenever they truly repent of their sins.
XIII Of the Use of the Sacraments: affirms that the Sacraments are physical manifestations of God’s Word and His commitment to us, never just physical elements.
XIV Of Ecclesiastical Order: affirms that those who publicly preach or administer the Sacraments must be properly called.
XV Of Ecclesiastical Usages: affirms that church holidays, calendars and festivals are useful for religious observance, but that observance and ritual are not necessary for salvation.
XVI Of Civil Affairs: affirms that lawful civil ordinances are good works of God instituted for the sake of good order, and that Christians are bound to obey the laws of the land and those in authority except when commanded to sin.
XVII Of Christ’s Return to Judgment: affirms that Christ will return to raise the dead and judge the world; the godly will be given everlasting joy, and the ungodly will be tormented without end.
XVIII Of Free Will: affirms that we possess some measure of freedom of the will which enables us to live an outwardly honorable life and to make choices based on reason. However, our wills do not have the power, without the Holy Spirit, to make us acceptable to God.
XIX Of the Cause of Sin: affirms that sin is caused not by God but by the will of the wicked, turning away from God.
XX Of Good Works: affirms that justification by faith does not condemn good works; faith causes them to do good works as a sign of our justification (or salvation), not a requirement for salvation.
XXI Of the Worship of the Saints: affirms that remembrance of faithful Christians may serve as an example so that we may imitate their faith and good works, but the only mediator is Jesus Christ.
Concerning abuses –
XXII Of Both Kinds In The Sacrament: It is proper to offer communicants the consecrated bread and wine, not just the bread.
XXIII Of the Marriage of Priests: the clergy should be allowed to be married, for the reasons that the early Church bishops were married, that God blesses marriage as an order of creation, and because marriage and procreation is the natural outlet for human sexual desire.
XXIV Of the Mass: the Mass should be only as a public gathering for the purposes of community worship and the receiving of the Eucharist, and not a work for salvation or worldly gain.
XXV Of Confession: there is a need for confession and absolution, but confession should not induce guilt or anxiety to the Christian. Absolution is offered for all sin, not just sins that can be recounted in a confession, as it is impossible for anyone to know all of their transgressions.
XXVI Of the Distinction of Meats: Human traditions that hold fasting and special observances with dietary restrictions as a means of gaining the favor of God are contrary to the gospel. While fasting and other practices are useful spiritual practices, they do not justify man nor offer salvation.
XXVII Of Monastic Vows: Man cannot achieve purity in community or isolation from the rest of the world, and perfection cannot be attained by any vow taken or actions of man alone.
XXVIII Of Ecclesiastical Power: The only power given to priests or bishops is the power offered through Scripture to preach, teach and administer the sacraments. The powers given to the clergy in issues of government or the military are granted and respected only through civil means; they are not civil rulers of governments and the military by divine right.