Tentatio (Trial)

Lastly, we come to part three of Luther's instruction to study theology: Third, there is the tentatio, the trial. This is the touchstone. It teaches you not only to know and understand, but also to experience how right, how true, how sweet, how lovely, how mighty, how comforting God's Word is: it is wisdom supreme. This is why you observe that, in the psalm indicated, David so often complains of all sorts of enemies...For as soon as God's Word becomes known through you, the devil will afflict you, will make a real [theologian] of you (from What Luther Says: An Anthology compiled by Ewald M. Plass).

Psalm 119

67 Before I was afflicted I went astray: but now have I kept thy word.
68 Thou art good, and doest good; teach me thy statutes.

71 It is good for me that I have been afflicted; that I might learn thy statutes.