Aeschylus said when you learn you suffer. It is really true. The more you know the more you suffer if you have any empathy or sympathy or brains for that matter. The knowledge that we gain of the world and the fact that God loved it so much he sent Christ to die for us and that we take it so for granted should cause us to suffer.
Luther loved Psalm 119. Psalm 118 he called his “beloved and favorite” but from Psalm 119 that he probably prayed daily, he got the idea that that to be a theologian (anyone who talks and thinks about God) which we should all want to be, and to be a proper one, Psalm 119 can lead the way. Psalm 118 is a psalm of thanksgiving. Psalm 119 is a Psalm of comfort. From this Psalm Luther came up with the famous statement that to be a theologian you must pray, meditate and suffer. Some prefer testing to suffer, but as Aeschylus said, “He who learns, suffers”.
Here is Luther –
I want to point out to you a correct way of studying theology, for I’ve had practice in that. If you keep to it, you will become so learned that you yourself could (if it were necessary) write books just as good as those of the fathers and councils. This is the way taught by holy King David (and doubtlessly used also by all the patriarchs and prophets) in Psalm 119. There you will find three rules, amply presented throughout the whole psalm: prayer (oratio), meditation (meditatio), and testing (tentatio).
First, you should know that the Holy Scriptures constitute a book that turns the wisdom of all other books into foolishness, because not one teaches about eternal life except this one alone. Therefore you should straightway despair of your reason and understanding. With them you will not attain eternal life, but, on the contrary, your presumptuousness will plunge you and others with you out of heaven (as happened to Lucifer) into the abyss of hell. But kneel down in your room and pray to God with real humility and earnestness (as David did), that he through his dear Son may give you his Holy Spirit, who will enlighten you, lead you, and give you understanding.
Second, you should meditate not only in your heart, but also externally, by actually repeating and comparing oral speech and literal words of the book, reading and rereading them with diligent attention and reflection, so you may see what the Holy Spirit means by them. Take care you do not grow weary or think you have done enough when you have read, heard, and spoken them once or twice, and that you then have complete understanding. You’ll never be a particularly good theologian if you do that, for you will be like untimely fruit which falls to the ground before it is half ripe. God will not give you his Spirit without the external Word.
Third, there is testing. This is the touchstone that teaches you not only to know and understand, but also to experience how right, how true, how sweet, how lovely, how mighty, and how comforting God’s Word is, wisdom beyond all wisdom. David, in Psalm 119, complains often about all kinds of enemies, arrogant princes or tyrants, false spirits and factions, whom he must tolerate because he meditates, that is, because he is occupied with God’s Word in all manner of ways. For as soon as God’s Word takes root and grows in you, the Devil will harry you and will make a real theologian of you, for by his assaults he will teach you to seek and love God’s Word. I myself am deeply indebted to my critics, that through the Devil’s raging they have beaten, oppressed, and distressed me so much. That is to say, they have made a fairly good theologian of me, which I would not have become otherwise. And I heartily grant them what they have won (honor, victory, and triumph) in return for making this of me, for that’s the way they wanted it.