Anfechtung 3 "God in his mercy ordains their sufferings and difficulties for them..."

  Let us ask further whether, when everything goes wrong [in the believer’s life] with their life, their goods, their honor, their friends, or whatever they have, they still believe that their works are well-pleasing to God, and that God in his mercy ordains their sufferings and difficulties for them, whether they be small or great.
  The great thing in life is to have a sure confidence in God when, at least as far as we can see or understand, he shows himself in wrath, and to expect better at his hands than we now know.
  Here God is hidden, as the bride says in the Song of Songs [2:9], “Behold there he stands behind our wall, gazing in through the windows.”
  That means he stands hidden among the sufferings which would separate us from him like a wall, indeed, like a wall of a fortress.
  And yet he looks upon me and does not forsake me. He stands there and is ready to help in grace, and through the window of dim faith he permits himself to be seen. And Jeremiah says in Lamentations 3[:39–33], “He casts men aside, but that is not the intention of his heart.”
  These people know nothing at all of this kind of a faith, and they give themselves over to thinking that God has forsaken them and is their enemy. They even lay the blame on other men or on the devil, and have simply no confidence at all in God. For this reason, too, their suffering is always an offense to them and harmful. And yet they go on doing their good works, as they think, quite unaware of their serious unbelief.
  But they who in such suffering trust God and hold on to a good, firm confidence in him, who believe that he is well-pleased with them, see in their sufferings and afflictions nothing but pure and precious merits, the costliest treasures which no man can assess.
  For faith and confidence make precious before God all that which others think most shameful, so that it is written even of death in Psalm 116[:15], “Precious in the sight of the Lord is the death of his saints.” And just as confidence and faith are better, higher, and stronger at this stage than in the first, so the sufferings which are borne in this kind of faith excel all works of faith. Therefore there is an immeasurable difference between such works and sufferings, and the sufferings are better.
  Beyond all this is the highest stage of faith, when God punishes the conscience not only with temporal sufferings but with death, hell, and sin, and at the same time refuses grace and mercy, as though he wanted to condemn and show his anger eternally. Few men experience this as David did when he complained in Psalm 6[:1], “O Lord, rebuke me not in thy anger.”
  To believe at such times that God is gracious and well-disposed toward us is the greatest work that may ever happen to and in a man, but of this the work-righteous and the doers of good works know nothing at all. For how would they know to expect God’s goodness and grace in these circumstances when they are not certain about the works they do and have doubts at the lowest stage of faith?

Martin Luther - The Christian in Society I.
(Luther's Works 44), S. 44:27