In 2003 the Movie Luther was released. One of the reasons I like the movie so much, and think you should watch it, is because it is almost exactly historically accurate. My favorite quote from the movie comes when Luther (played by Joseph Fiennes) is preaching and says this:
Those who see God as angry, do not see him rightly. If we truly believe that Christ is our Savior, than we have a God of Love, and to see God in faith is to look upon His friendly heart. So when the devil throws your sins in your face and declares that you deserve death and hell, tell him this: I admit that I deserve death and hell, what of it? For I know one who suffered and made satisfaction in my behalf, his name is Jesus Christ Son of God, where He is, there I shall be also!