https://www.biblegateway.com/passage/?search=Romans%207%3A19-25&version=NKJV;NIV
Was Paul crazy? I don't think so.
Did Luther perhaps encounter the same thing within himself -- which Paul did? We just might be able to venture that yes he did.
And where did Luther find his relief -- not from within and amid the Church of his own time & place -- but from the written word, and even from Paul.
It really is no wonder that Luther (and others too) was among others things --- so driven to translate the written word into language that the common man could understand.
This fits another of my theories. In general, I tend to find Protestants/Others take a view if the Apostles and Prophets/Patriarchs that tries to bring those men of God down to the level of the audience, to make them seem as neither worthy of veneration or obedience, but as fellows just like them, who often had no clue what they were up to. That would fit the model of every man and woman deciding individually what, and who, merits their obedience. It also makes it easier to ignore certain passages of Jesus when convenient.
Since Catholics tend toward the opposite view, upholding them in veneration and obedience, it really makes for an interesting contrast.
Relief, eh? And so because of Luther's fear, lack of faith and disordered desire to save his own skin we have millions of souls who got their "assurance". Good for them. It only cost us Western Civilization and possibly their immortal soul. Enjoy.