In a world that is filled with falsehoods, illusions, and utopias, the essential prerequisite for understanding human sinful nature is the critique shaped by the Word of God. Reformer Dr. M. Luther, with his focus on the cross and so-called theology of the cross, has been one of the most outspoken critics of human sinfulness. He contrasts this theology of the cross with the so-called theology of glory, thereby opposing human nature’s efforts at self-justification. In modern times, this manifests as popular movements of self-improvement and self-help, as well as the revered hopes for progress in science and technology or today’s great optimism about the development of artificial intelligence. In this regard, Luther’s theology of the cross serves as a valuable tool to distinguish the true from the false in matters related to human salvation and the healing of sin’s wounds.