Luther on Peace of Conscience

The world advances free will, the rational and natural approach of good works, as the means of obtaining the forgiveness of sin. But it is impossible to gain peace of conscience by the methods and means of the world. Experience proves this. Various holy orders have been launched for the purpose of securing peace of conscience through religious exercises, but they proved failures because such devices only increase doubt and despair. We find no rest for our weary bones unless we cling to the word of grace.

~Martin Luther, Commentary on Galatians 1:3.