Kolb, Robert. The Book of Concord: The Confessions of the Evangelical Lutheran Church. Minneapolis: Fortress Press, 2000.
Augsburg Confession I, “Concerning God” p. 30.
Apology to the Augsburg Confession I, “God” p. 111
The first article of the Confession teaches that there is one God, one essence, in three persons, equal in power and eternity. The article identifies numerous attributes of God. It specifies that in the term “person” the idea of a part is not intended, but a whole. The article rejects all non-Trinitarian views including specifically those which confess one God who takes on different forms at different times.
The first article of the Apology confirms that the Evangelicals and the Roman Church agree in their view of the Trinity. Likewise, there is mutual rejection of those who reject this historic doctrine.