Hello! Although both Erasmus and Martin Luther wanted to reform the Church, both disagreed on the correct methods of bringing about the desired changes. Below, I list the contrasts between Erasmus and Martin Luther in their attitudes and roles to the reform of the Catholic Church in the 16th Century.
1) Erasmus favored a less militant approach to reform. He was open to persuasion and to debate. Luther was more dogmatic (immovably opinionated). Each accused the other of having the right intentions but the wrong solutions.
2) Erasmus did not want to sacrifice peace within the Church; he hated discord and contention. On the other hand, Luther insisted that if the Church was to be cleansed of all impurities, an uncompromising allegiance to absolute dogma was a necessity. Luther felt that Erasmus did not possess the necessary characteristics or aptitude to be an effective reformer. He scoffed at Erasmus' apparent lack of earnestness and Erasmus in turn, was horrified at Luther's brash insensitivity.
3) Theological differences: Both Erasmus and Luther disagreed on the theological definition of free will. Erasmus did not want to rock the boat too much; he felt that the authority of Scripture and the authority of church tradition were of equal consequence. On the other hand, Luther believed in Sola Scriptura (by Scripture alone) and sola fide (justification by faith alone).
Luther attested that salvation was the work of God alone. He believed that the idea of free choice was an illusion, and that the imperfection of human nature rendered any claim to salvation by works impossible. Meanwhile, Erasmus believed in theological synergism. This is the concept of God and man working together for one's soul salvation.
This theological difference was at the heart of the conflict between Erasmus and Luther during the Reformation. Both men were bitterly opposed to the other's definition of salvation. To argue their points, Luther wrote The Bondage of The Will, and Erasmus, The Freedom Of The Will.