In theological theses prepared for the Heidelberg Disputation (1518), the young Luther laid out his emerging theology. He distinguished two approaches, between a “theology of glory” and a “theology of the cross.”
Luther characterized the dominant theology of his day as a “theology of the glory,” which sought to know of God’s invisible nature through speculating on God’s divine power and wisdom, through God’s works in creation (see Rom. 1:20–23). This could lead persons to think that they are “worthy and wise.”
But for Luther, this misses the fact that humans are sinful and now must know the true God only in relation to their sin and God’s divine judgment. They must know God through a “theology of the cross,” where God is both hidden and revealed in Jesus Christ. God is hidden in what the world considers “foolish” (1 Cor. 1:25), in Jesus’ humanity, weakness, and suffering. Luther put it starkly: “God can be found only in suffering and the cross” (LW 31:53).
Faith recognizes God in the shame and suffering of Christ on the cross. Theology is about salvation and not about philosophical ideas. We encounter the true God in the man Jesus, who as the Son of God, suffered as the means to the gift of salvation—unattainable through human reason, good works, or ethical actions. The “wisdom of the wise” is destroyed.