Religious in his temper and training, and educated in a creed which worked mainly on man’s fears, without emphasizing the only basis of spiritual peace, he fell into great terrors of conscience.  Several occurrences contributed to this:  (1) He fell sick, and was likely to die. (2) He accidentally severed an artery, and came near bleeding to death. (3) A bosom friend of his was suddenly killed.  All this made him think how it would be with him if called to stand before God in judgment, and filled him with alarm.  Then (4) he was one day overtaken by a thunderstorm of unwonted violence.  The terrific scene presented to his vivid fancy all the horrors of a mediaeval picture of the Last Day, and himself about to be plunged into eternal fire.  Overwhelmed with terror, he cried to Heaven for help, and vowed, if spared, to devote himself to the salvation of his soul by becoming a monk.  His father hated monkery, and he shared the feeling; but, if it would save him, why hesitate?  What was a father’s displeasure or the loss of all the favors of the world to his safety against a hopeless perdition?

Call it superstition, call it religious melancholy, call it morbid hallucination, it was a most serious matter to the young Luther, and out of it ultimately grew the Reformation.  False ideas underlay the resolve, but it was profoundly sincere and according to the ideas of ages.  It was wrong, but he could not correct the error until he had tested it.  And thus, by what he took as the unmistakable call of God, he entered the cloister.

Never man went into a monastery with purer motives.  Never a man went through the duties, drudgeries, and humiliations of the novitiate of convent-life with more unshrinking fidelity.  Never man endured more painful mental and bodily agonies that he might secure for himself an assured spiritual peace.  Romanists have expressed their wonder that so pure a man thought himself so great a sinner.  But a sinner he was, as we all; and to avert the just anger of God he fasted, prayed, and mortified himself like an anchorite of the Thebaid.  And yet no peace or comfort came.

A chained Bible lay in the monastery.  He had previously found a copy of it in the library of the university.  Day and night he read it, along with the writings of St. Augustine.  In both he found the same pictures of man’s depravity which he realized in himself, but God’s remedy for sin he had not found.  In the earnestness of his studies the prescribed devotions were betimes crowded out, and then he punished himself without mercy to redeem his failures.  Whole nights and days together he lay upon his face crying to God, till he swooned in his agony.  Everything his brother-monks could tell him he tried, but all the resources of their religion were powerless to comfort him or to beget a righteousness in which his anguished soul could trust.