With help from the old monk and Staupitz, but especially from the study of Paul’s Epistles, Luther gradually was brought to the conviction that the sinner is justified by faith alone, without works of law. By the end of his convent life he came to the conclusion that “the righteousness of God” (Rom. 1:17) is the righteousness which God freely gives in Christ to those who believe in him. Righteousness is not to be attained through man’s own exertions and merits. Rather, it is complete and perfect in Christ, and all the sinner has to do is to accept it from Him as a free gift. Justification is that judicial act of God whereby he acquits the sinner of guilt and clothes him with the righteousness of Christ on the sole condition of personal faith which apprehends and appropriates Christ and shows its life and power by good works, as a good tree bringing forth good fruits. This experience acted like a new revelation on Luther. It shed light upon the whole Bible and made it a book of life and comfort. He felt relieved of the terrible load of guilt by an act of free grace. From then on the doctrine of justification by faith alone was the very substance of the Gospel and the heart of theology. He measured every other doctrine and the value of every book of the Bible by this standard. That is the reason for his great enthusiasm for Paul, and his dislike of James, whom he could not reconcile with his favorite apostle.
In this way Luther’s monastic and ascetic life was a preparation for his evangelical faith. It was the tutor that lead him to Christ (Rom. 3:20; Gal. 3:24). He was ordained to the priesthood, and on May 2, 1507, he said his first mass. This was a great event in the life of a priest. He was so overwhelmed by the gravity of offering the tremendous sacrifice for the living and the dead that he nearly fainted at the altar.
An interesting event in his training for the Reformation was his visit to Rome. In the fall of 1510 he was sent to Rome at the suggestion of Staupitz, who wished to bring about a disciplinary reform of the Augustinian convents in Germany. Rome was filled with enthusiasm for the renaissance of classical literature and art, but was unconcerned with religion. Julius II, pope from 1503 to 1513, bent all his energies on the enhancement of the secular dominion of the papacy by means of an immoral diplomacy and bloody wars. When Luther came in sight of the city, he exclaimed, “Hail to thee, holy, Rome! Thrice holy for the blood of martyrs shed here.” In his own words, he ran around like a “crazy saint” going to all the churches, crypts and catacombs with an unquestioning faith in the legendary traditions about the relics and miracles of martyrs. He even climbed the 28 steps of the Scala Santa (said to have been transported from the Judgment Hall of Pontius Pilate in Jerusalem), on his knees. But at every step he seemed to hear the word of the Scripture as a protest in his ear: "The just shall live by faith" (Rom. 1:17). So here, even at the height of his ascetic career he doubted its efficacy in giving peace to the troubled conscience. This doubt was strengthened by everything he saw around him. He was shocked by the unbelief, levity and immorality of the clergy.
Money and luxurious living seemed to have replaced apostolic poverty and self-denial.
In the year 1502 Frederick III, surnamed the Wise, Elector of Saxony, founded a new University at Wittenberg. Wittenberg was a poor and badly built town of about three thousand inhabitants in a dull, sandy, sterile plain on the banks of the Elbe, and owes its fame entirely to the fact that it became the nursery of the Reformation theology. Luther says that it lay a few steps from barbarism, and speaks of its citizens as wanting in culture, courtesy and kindness. He felt at times strongly tempted to leave it. Melanchthon complained that he could not get a decent meal at Wittenberg. The university was opened October 18, 1502. The organization was entrusted to Dr. Pollich and to Staupitz, the first Dean of the theological faculty, who fixed his eye on his friend
Wittenberg soon overshadowed its powerful rivals in Erfurt and Leipzig by the new theology. The number of students was four hundred and sixteen in the first semester, then declined to fifty-five in 1505, partly in consequence of the pestilence, began to rise again in 1507, and when Luther and Melanchthon stood on the summit of their fame, they attracted thousands of pupils from all countries of Europe. At times Melanchthon heard eleven languages spoken at his table.