One of these apostates was John of Valladolid. At Burgos the discussion took place before Archbishop Gomez of Toledo. At Avila the whole community was compelled to repair to the great church (1375), where the debate was carried on in the presence of many Christians and Mahometans. Moses Cohen de Tordesillas, who was as familiar with Christian as with Jewish theological authorities, appeared on behalf of the Jews. He entered upon his dangerous enterprise with trepidation, for he had had an opportunity to form an estimate of Christian charity. During the civil war, Christian marauders had robbed him of all his possessions, and had even personally ill-used him in order to force him to embrace Christianity. All these trials he had suffered with the courage of strong convictions, but he had become so poverty-stricken that he had to accept support from the community of Avila.
Moses de Tordesillas did not find his part in the discussion too difficult. The apostate John of Valladolid laid stress on the proposition that the dogmas of Christianity--the Messianic claim, the Divinity and Incarnation of Jesus, the Trinity, and the Virginity of the "Mother of God"--could be demonstrated from the Old Testament. It was consequently not difficult for his Jewish opponent to confute his arguments. After four debates John was obliged to abandon his task, vanquished. This, however, did not conclude the matter. A pupil of the apostate, Abner-Alfonso, appeared soon after, and challenged Moses de Tordesillas to a debate on the Talmud and Agadic texts. In case of refusal, he threatened publicly to impeach the Talmud as the source of anti-Christian sentiments. Moses was again forced to meet a series of silly assertions and charges, and to drag himself through the thorny length of another controversy. By the advice of the Avila community, he committed to writing the principal arguments used in these discussions under the title, "Ezer ha-Emuna," and sent them to his Toledan brethren for use under similar circumstances. Moses de Tordesillas' disputations, notwithstanding the difficulties of his position, were characterized by calmness and equanimity. Not a word of abuse or invective escaped him, and he counseled his Toledo brethren not to permit themselves to be tempted by their zeal to vexatious expressions, "for it is a fact," he said, "that the Christians possess the power and disposition to silence truth by force." Toledo, formerly recognized as the teacher of Jewry, was now obliged to play the part of pupil, and follow formularies in the disputations to which its members might be invited.