The Imam’s presence in Khorasan was a great opportunity for the locals to directly ask him questions. Ma’mun himself also asked many questions from the Imam in public and private meetings. Ma’mun, who himself was knowledgeable in the Islamic faith, had asked the Imam many questions regarding the interpretations of the Quran, the traditions of the Prophet, and the fundamentals of the Shia belief. The Imam provided him with convincing answers.
Ma’mun arranged a series of debates in his palace between the Imam and the well-known Islamic and non-Islamic scholars. His intention was to defeat and disgrace the Imam during the scientific debates. If Ma’mun would have been able to fulfill his intention, he would have ruined the Imam’s reputation in the eyes of the Muslims, who respected the Imam for his endless knowledge. In the most famous debate, Ma’mun gathered the leaders of Christians, Jews, Zoroastrians, and Sabians in his palace. He held a grand official event for their debate with the Imam. Crowds of people and government officials attended. The Imam knew that there would not be a common ground with the leaders of the other religions for the debate, because they would deny the Imam’s reasoning with Quranic evidence and the traditions of the Holy Prophet. To everyone’s surprise, the Imam debated each of the leaders according to their respective holy books. The Imam demonstrated that his knowledge was not limited to Islamic resources, and that he was more knowledgeable than the leaders in their own teachings.
The Imam first debated with the Christian leader. The Christian leader asked him to bring two witnesses who had testified to the prophethood of Prophet Muhammad (PBUH) and were approved by the Christians. The Imam recited parts of the Gospel in which Prophet Jesus and his apostle had spoken about the last Prophet. During the debate, the Imam said that he believed in Prophet Jesus, but had only found one flaw about him. The Imam said that Prophet Jesus did not pray or fast much. The Christian leader surprisingly responded, “You are wrong because he fasted every day and prayed every night.” The Imam then asked him, “If that was the case, who was he praying to and fasting for?” Through this, the Imam challenged the Christian belief that Prophet Jesus is God’s manifestation on earth, because if he were God, he would not pray to himself. With the Imam’s reasoning, the leader became silent.
The Imam then asked the Christian leader why he denied that Prophet Jesus was able to give life to the dead with God’s power rather than with his own. The leader responded that someone who could raise the dead and heal the blind was indeed God himself, and deserved worship. The Imam then brought forth multiple cases of evidence from the Gospel, Torah, Psalms, and Quran where the other Prophets such as Elisha, Ezekiel, Abraham, Moses, and Muhammad (PBUH) also performed miracles of resurrecting the dead. The Imam himself recited the related parts from Torah and t