Machiavelli's advice to distrust mercenaries, stave off contempt and hatred, and rely on one's own arms was a result of his understanding of a need for an organized political system capable of crushing opposition. He suggests that ruthless policies are the most effective way to achieve political reform. Machiavelli is not concerned over the justness of his reformation policies, as long as they allow for the most efficiently run political structure. .
Unlike Machiavelli's political problems with authority, Luther's contentions are primarily theological. Luther's problem with Catholic authority was its emphasis on works as a means of justification. In "The Freedom of a Christian," Luther notes that works such as transubstantiation are considered truly damnable when they are practiced under the false impression that, through them, one is justified. Luther instead argued that for man to be justified, he must adhere to the principle of sola fide, or faith over all else. This idea countered the papacy's primary emphasis on justification through works during this time. Luther believed that whatever could be accomplished through actions alone could be accomplished more easily through certitude in faith, which best demonstrates man's highest worship of God. While Luther and Machiavelli have fundamentally different approaches to reform, they both pursue the most direct solution to advance society. Machiavelli believes that the most direct measure is ruthless conquest for political gains, while Luther believes that faith brings one directly closer to God. .
While Machiavelli focused mainly on political thought, and Luther theological, the two addressed each other's respective areas of focus. Machiavelli also commented on the role of religion in a well-run political society. Machiavelli viewed religion as a useful instrument for princes to rule a civilized state. In The Discourses, he said that people are more afraid of breaking an oath and going against the power of God than breaking a law ruled by man.