Battling a Sensitive Conscience

This is the nature and the true color of the devil, whereby he is to be recognized. He is such a wicked fellow that he can belittle a great sin to keep one from seeing it, and, on the other hand, can magnify a little sin for the purpose of causing one to worry, torture, and kill oneself with it. That is why a Christian should learn not to let anyone easily create an evil conscience in him; but if he believes in Christ, would gladly be pious, fights against sin to the best of his ability, yet goes wrong, failing and faltering at times, then he should not let this failing spoil his good conscience. Rather let him say: Let this error and this failing pass away with my other imperfections and sins, which I must include in the article of faith: I believe in the forgiveness of sins, and in the Fifth Petition of the Lord's Prayer: Forgive us our trespasses.

Source: Quoted in Ewald M. Plass, What Luther Says, A Practical In-home Theology for the Active Christian. St. Louis: Concordia Publishing House. 1959 Edition, 10th Printing (1994), pp. 333-334.