On the other hand, what great joy and strength a tranquil heart has can be seen in the saintly martyrs, who laughed in the midst of suffering and death and praised God. This the ungodly cannot do; for they have a guilty conscience, which leads them to blaspheme, be angry with God, and hate Him with all their hearts.
Let us learn, then, even from fear of punishments and that incurable evil which is a wounded heart to beware of falling into sin; for it is exceedingly difficult to wrestle with the consciousness of sin. It is easy to fall, but to retrace one’s step and breathe once again the air of the kindness and mercy of God—this is toil, this is labor.
Luther’s works, vol. 8: Lectures on Genesis: Chapters 45-50