Lutheran theology affirms the classical Christian understanding of God as one infinite, eternal, omnipotent, omniscient, and perfectly holy divine being. God is transcendent Creator and also intimately personal — the God who speaks through Scripture, acts in history, and is truly present in Word and Sacrament. This doctrine is grounded in the Augsburg Confession Article I and the Nicene Creed.

A distinctively Lutheran emphasis is that God is known supremely through the theology of the cross (theologia crucis), not through speculative natural theology. Luther developed the contrast between the 'hidden God' (Deus absconditus) and the 'revealed God' (Deus revelatus) — God is most fully known not in glory and power but in the suffering and humiliation of Jesus Christ on the cross. This shapes Lutheran piety and worship.