For you bless the righteous, O Lord; you cover him with favor as with a shield. (Psalm 5:12 ESV)
Whoever would be righteous must first become a sinner; whoever wants to be well, good, and like God as a Christ-like member of the church must first become sick, bad, perverted, devilish, even heretical – as unbelieving as a Turk – as Paul says, “Whoever among you would be wise must first become foolish in order to be wise.” Let this statement stand, for it is God’s will in heaven that He has intended through foolishness to create wisdom; through wickedness to create the good; through sin to create righteousness; through folly, even through sickness to create health; through heresy to create churchliness; through unbelief the believer; and through the form of the devil to create godly people. You ask, “How?” It shall be answered briefly and quickly. You cannot become before God someone that you would like to be if you first have not become before yourself and before others the kind of person He wants you to be. God does intend, however, that you should become before yourself and others what you really are – namely, a sinner; bad, sickly, perverse, and devilish. Those are your names. Those are the things that you are in truth and they are your humiliation. As soon as that happens you are already before God what you wanted to be: holy, good, true, straight, and pious. On this basis you become a new person before yourself, others, and before God. Why are you surprised? Why are you bothered when you displease yourself and others? Because if you don’t displease them, them you can’t please God.
Martin Luther, “Operationes in Psalmos”, WA 5:195:41-196:15. Quoted in Hans Iwand’s “The Righteousness of Faith According to Luther”, pages 72-73