When at Bourges Calvin seems to have abandoned the study of the law, and turned again to the church as he now saw it in the holy scriptures. He applied himself to the study of the Greek language, and also to Hebrew and Syriac, in order to the better understanding of the Old Testament, for theology was still the favorite object of his attention. He was also most willing to make known the truth to others in which he now believed and delighted. Listeners flocked around him, and the solitude he loved became impossible to him. "As for me," he says, "inasmuch as being naturally diffident and retiring, I have always preferred repose and tranquility; I began to seek for some hiding-place, and means of withdrawing myself from the world, but, so far from obtaining my wish, every retreat and every secluded spot were to me so many public schools." But he was not of those who are silent on what they believe. He preached in the secret meetings at Bourges and at Paris. Theodore Beza says, "He advanced wonderfully the cause of God in many families, teaching the truth not with an affected language, to which he was always opposed, but with a depth of knowledge and so much gravity of speech, that no man heard him without being filled with admiration."
Calvin once more ventured to Paris. He had fondly hoped that France might be the sphere, and Paris the center of his work; but the violence of the persecution compelled him to conceal both himself and his intentions. He was now about twenty-four years of age, and full of zeal and activity. One of his friends, Nicholas Cop, son of a citizen of Basle, who was first physician to the king, and rector of the university of Paris, had to deliver an oration according to custom on All Saints' Day. What an opportunity, suggested Calvin to his friend Cop, of having the gospel preached in the most public of all the pulpits of Christendom! But, Cop feeling unequal to the task of composing such an address, it was agreed that Calvin should write and that Cop should read the oration. On the 1st of November, 1533, in the midst of the learned men of Paris, the rector delivered his address to a silent and surprised audience. Calvin had forgotten to say anything about the saints, though it was "All Saints' Day," but extolled the grace of God as man's only hope of pardon and salvation through the precious sacrifice of Christ.
When the assembly rose, the storm burst forth. It was denounced as treason against the saints, and a blow struck at the very foundations of Rome. But Cop was the king's first physician and a great favorite; what was to be done? He was denounced by the Sorbonne to the parliament, and to the executioner of heretics. Cop saw his danger in time, fled to Basle, and so escaped the flames of martyrdom. Cop was gone, but his friend Calvin was suspected of being the real author of the oration. The lieutenant-criminal, the notorious John Morin, had orders to apprehend him. While sitting safely, as he thought, in his obscurity, a fellow-student rushed into his chamber, begging him to flee that instant; the serjeants were at the outer gate. Dropping from the window by means of a sheet, he escaped; and under the name of Charles Heppeville, clothed in a peasant's dress, with a garden hoe on his shoulder, he reached Angouleme, and was received into the house of the Canon Louis du Tillet, where he stayed for some time, and had a rich library at his service.