“Let us fix our mind on other thoughts,” Luther had also said to Schlaginhaufen, “on thoughts of dancing, or of a pretty girl, that also is good. Gerson too wrote of this.”[521] As a matter of fact, Gerson certainly wrote nothing about getting rid of temptations by means of sensual images. On the contrary, in the passages in question of his spiritual writings, he teaches something quite different and insists, first and foremost, on the avoidance of sin. He proposes our doing the exact opposite of the wicked or unworthy acts suggested by the evil spirit. He, like all Catholic masters of the spiritual life, indeed instructs those tempted to distract their minds, but by pious, or at least, indifferent and harmless means.[522] 2. Some of Luther’s Practical Principles of Life We find in Luther no dearth of strong expressions which, like his advice to Weller and Schlaginhaufen, seem to discountenance fear of sin, penance and any striving after virtue. It remains to determine from their context the precise meaning which he attached to them. _Luther on Sin_ As early as 1518 Luther, in a sermon at Erfurt, had given vent to the words already quoted: “What does it matter whether we commit a fresh sin so long as we do not despair but repeat: Thou, my God, still livest, Christ, my Lord, has destroyed sin; then at once the sin is gone.... The reason why the world is so out of joint and lies in such error is that there has been no real preacher for so long.”[523] “Hence we say,” so later on we read in his exposition of John xvii., “that those who are true Saints of Christ must be great sinners and yet remain Saints.... Of themselves, and for all their works, they are nothing but sinners and under condemnation, but by the holiness of another, viz. of the Lord Christ, bestowed on them by faith, they are made holy.”[524] And further: “The Christian faith differs greatly from the faith and religion of the Pope and the Turks, etc., for, by it, in spite of his consciousness of sin, a man, amidst afflictions and the fear of death, continues to hope that God for Christ’s sake will not impute to him his sin.... But so great is this grace that a man is startled at it and finds it hard to believe.”[525]—He himself and many others often found it difficult, indeed terribly difficult, to believe. They were obliged to “reassure themselves” by the Word of God. A few more quotations may here be added. “To be clean of heart not only means not to harbour any impure thoughts, but that the conscience has been enlightened and assured by the Word of God that the law does not defile; hence the Christian must understand that it does not harm him whether he keeps it [the law] or not; nay, he may even do what is otherwise forbidden, or leave undone what is usually commanded; it is no sin in him, for he is incapable of sinning because his heart is clean. On the other hand, an impure heart defiles itself and sins in everything because it is choked with law.”[526]