In the spring of 1518 a general assembly of the Augustinian order was held at Heidelberg: Luther, by invitation, was present. His friends, knowing the designs and treachery of the Dominicans, did all they could to dissuade him from going; but Luther was not the man to be hindered by the fear of danger from the accomplishment of what he believed to be his duty. His trust was in the living God. So favorable an opportunity for preaching the gospel, the spread of the truth, and the diffusion of his propositions, was not to be neglected. He started on the 13th of April, with a guide who assisted him to carry his baggage, and performed the greater part of the journey on foot.
General curiosity, the name of Luther, the fame of his theses, attracted large crowds to the city and the university of Heidelberg. Here, before a large assembly, he disputed with five doctors of divinity on a variety of subjects, but relating chiefly to theology and philosophy. His knowledge of scripture, of the traditionary dogmas of the church, his want of respect for the name and system of Aristotle, his great argumentative power, proved to his opponents that he was a polemic of no common order. He returned to Wittemberg, well protected and accompanied by many friends.
The wonderful effect produced by these controversies moved Tetzel to attempt a reply to Luther's attack on the sale of indulgences. Full of vain boasting and blasphemy, he asserts and reasserts the power of the pope, and of the clergy as deputed by him, fully and forever to forgive all sins. In answer to these daring assertions, Luther wrote a further series of propositions which he termed "Resolutions," or explanations of his former theses. In this treatise the Reformer is more distinctly seen. He brings prominently forward the great truth of the Reformation—that man is justified by faith alone without deeds of law. "For he hath made him [Christ] to be sin for us, who knew no sin; that we might be made the righteousness of God in him." (2 Cor. 5:2121For he hath made him to be sin for us, who knew no sin; that we might be made the righteousness of God in him. (2 Corinthians 5:21).)
Luther now challenges the decision of the pope himself. He sent him a copy of his Resolutions, accompanied by a very humble letter, dated May 30th, 1518. Utterly careless as Leo really was as to the interests of religion, he could not treat with entire indifference the letter of Luther; especially as the emperor Maximilian had solicited his interference about the same time. He ordered Luther to be sent to Rome and there to answer for his audacity. Luther refused to obey the summons, declaring, however, his readiness to appear and defend his cause before pious, impartial, and learned judges in Germany. The pope, finding that Luther was under the protection of Frederick elector of Saxony, wrote to that prince desiring him to deliver the heretical monk to the Cardinal Thomas Cajetan, who had full instructions how to act with regard to the disobedient doctor. But, to the praise of that singularly wise and excellent prince, he refused to obey the pope's orders and protected Luther. The pope was now obliged to propose less hasty, less blood-thirsty, and more formal measures. Accordingly the citation to Rome was changed into a summons to Augsburg, which Luther declared his intention to obey.