To Luther, however, the post of high dignity to which he was now promoted brought new fear and anxiety. He had now to appear before God as a priest; to have Christ's Body, the very Christ Himself, and God actually present before him at the mass on the altar; to offer the Body of Christ as a sacrifice to the living and eternal God. Added to this, there were a multitude of forms to observe, any oversight wherein was a sin. All this so overpowered him at his first mass, that he could scarcely remain at the altar; he was well-nigh, as he said afterwards, a dead man.
With these priestly functions he united an assiduous devotion to his saints. By reading mass every morning, he invoked twenty-one particular saints, whom he had chosen as his helpers, taking three at a time, so as to include them all within the week.
As regards the most important problems of life, his study of the Scriptures gradually revealed to him the light which determined his future convictions. The path had already been pointed out to him by the words of St. Paul quoted by St. Bernard. When looking back, at the close of his life, on this his inward development, he tells us how perplexed he had been by what St. Paul said of the 'righteousness of God' (Rom. i. 17). For a long time he troubled himself about the expression, connecting it as he did, according to the ruling theology of the day, with God's righteousness in His punishment of sinners. Day and night he pondered over the meaning and context of the Apostle's words. But at length, he adds, God in His great mercy revealed to him that what St. Paul and the gospel proclaimed was a righteousness given freely to us by the grace of God, Who forgives those who have faith in His message of mercy, and justifies them, and gives them eternal life. Therewith the gate of heaven was opened to him, and thenceforth the whole remaining purport of God's word became clearly revealed. Still it was only by degrees, during the latter portion of his stay at Erfurt, and even after that, that he arrived at this full perception of the truth.
After their ordination the monks received the title of fathers. Luther was not as yet relieved of the duty of going out with a brother in quest of alms. But he was soon employed in the more important business of the Order, as, for instance, in transactions with a high official of the Archbishop, in which he displayed great zeal for the priesthood and for his Order.