A few years later, he was a junior faculty member at a new university in small-town Germany, intently studying the Scriptures, “captivated with an extraordinary ardor for understanding Paul in the Epistle to the Romans.”

In these days Luther was tormented by the demand for righteousness before God. “I did not love, yes, I hated the righteous God who punishes sinners, and secretly, if not blasphemously, certainly murmuring greatly, I was angry with God.” Then, in the midst of that struggle with God, the message of the Scriptures became clear, like a long-shut door opening wide. When he realized that a “merciful God justifies us by faith … I felt that I was altogether born again and had entered paradise itself through open gates.”

What Luther discovered is the freedom of Christians trusting God’s mercy in Christ. As he later wrote, “Faith is God’s work in us.