From the beginning his lectures on theology differed from those ordinarily given, but not because he had any theological opinions at variance with those of his old teachers at Erfurt. No one attributed any sort of heretical views to the young Wittenberg professor. His mind was intensely practical, and he believed that theology might be made useful to guide men to find the grace of God and to tell them how, having acquired through trust a sense of fellowship with God, they could persevere in a life of joyous obedience to God and His commandments. The Scholastic theologians of Erfurt and elsewhere did not look on theology as a practical discipline of this kind. Luther thought that theology ought to discuss such matters, and he knew that his main interest in theology lay on this practical side. Besides, as he has told us, he regarded himself as specially set apart to lecture on the Holy Scriptures. So, like John Colet, he began by expounding the Epistles of St. Paul and the Psalms. Luther never knew much Hebrew, and he used the Vulgate in his prelections. He had a huge widely printed volume on his desk, and wrote out the heads of his lectures between the printed lines. Some of the pages still survive in the Wolfenbüttel Library, and can be studied.(145) He made some use of the commentaries of Nicholas de Lyra, but got most assistance from passages in Augustine, Bernard, and Gerson,(146) which dealt with practical religion,(147) His lectures were experimental. He started with the fact of man’s sin, the possibility of reaching a sense of pardon and of fellowship with God through trust in His promises. From the beginning we find in the germ what grew to be the main thoughts in the later Lutheran theology. Men are redeemed apart from any merits of their own; God’s grace is really His mercy revealed in the mission and work of Christ; it has to do with the forgiveness of sins, and is the fulfilment of His promises; man’s faith is trust in the historical work of Christ and in the verity of God. These thoughts were for the most part all expressed in the formal language of the Scholastic Theology of the day. They grew in clearness, and took shape in a series of propositions which formed the common basis of his teaching: man wins pardon through the free grace of God: when man lays hold on God’s promise of pardon he becomes a new creature; this sense of pardon is the beginning of a new life of sanctification; the life of faith is Christianity on its inward side; the contrast between the law and the gospel is something fundamental: there is a real distinction between the outward and visible Church and the ideal Church, which latter is to be described by its spiritual and moral relations to God after the manner of Augustine. All these thoughts simply pushed aside the ordinary theology as taught in the schools without staying to criticise it.