Martin Luther was a pioneer and leader of the German Reformation. In his youth, Luther systematically studied Catholic theology and studied the Bible. 15 1 1 year, Luther was sent by the monastery to worship the Vatican and witnessed the corruption of the Pope and the Catholic Church, which made him more and more suspicious of the missionary work of the church and sprouted the idea of reforming German religion. 15 12, Martin Luther received his doctorate in theology and was appointed as the vice president of Wittenberg monastery and professor of theology at Wittenberg university. He used the university library to study the Bible, from which he realized the truth that "believing in Jesus can be saved". He has initially denied the authority of the Pope and is determined to achieve national rejuvenation through reform. Firstly, it explains that the cornerstone and core idea of Martin Luther's religious reform is "justification by faith", and explains the content of "justification by faith". The core of Martin Luther's religious thought is "justification by faith". He believes that the salvation of human soul depends on individual's sincere belief in God, and the Bible is the only authority and basis for people's belief, which depends on the Pope and the sacraments. This fundamentally violates the traditional Catholic view that atonement can only be made through the church and the pope, and the soul can only enter heaven through complicated religious ceremonies. This argument is a heavy blow to the Pope and the Catholic Church. Then Martin Luther published "95 theses". The content of the ninety-five Outline denies the authority of the Pope and the church. It aroused the German people's opposition to the Vatican and opened the prelude to the religious reform in Europe. Make people understand the concept of "original sin" in Christian teachings. On this basis, we reformed from two aspects: doctrine and church organization, so as to understand the difference between Martin Luther's thought and church missionary, which is Martin Luther's religious reform thought.