The Deceiver can magnify a little sin for the purpose of causing one to worry, torture, and kill oneself with it. This is why a Christian should learn not to let anyone easily create an evil conscience in him. Rather let him say, "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.
Martin LutherTrue faith will no more fail to produce [good works] than the sun can cease to give light.
Martin LutherWhile we contemplate in all creatures, as in a mirror, those immense riches of His wisdom, justice, goodness and power, we should not meerly run them over cursorily, and, so to speak, with a fleeting glance, but we should ponder them at length, turn them over in our mind seriously and faithfully and recollect them repeatedly.
Martin LutherThere is on earth among all dangers, no more dangerous thing than a richly endowed and adroid reason, especially if she enters into spiritual matters which concern the soul and God. For it is more possible to teach an ass to read than to blind such a reason and lead it right; for reason must be deluded, blinded, and destroyed.
Martin Luther