Luther had been for a moment overawed on the evening before when he had to appear before so august an assembly. His heart had been agitated at the sight of so many princes before whom great kingdoms humbly bent the knee. The thought that he was going to refuse obedience to men whom God had invested with sovereign power gave him deep concern; and he felt the necessity of seeking strength from a higher source. "He who, attacked by the enemy, holds the shield of faith," said he one day, "is like Perseus holding the head of the Gorgon, on which whoever looked, that moment died. So ought we to hold up the Son of God against the snares of the devil."[519] On this morning of the 18th April, he had moments of trouble, when the face of God was hid from him. His faith becomes faint; his enemies seem to multiply before him; his imagination is overpowered.... His soul is like a ship tossed by a violent tempest, now plunged to the depths of the sea, and again mounting up towards heaven. At this hour of bitter sorrow, when he drinks the cup of Christ, and feels as it were in a garden of Gethsemane, he turns his face to the ground, and sends forth broken cries, cries which we cannot comprehend, unless we figure to ourselves the depth of the agony from which they ascended up to God.[520] "God Almighty! God Eternal! how terrible is the world! how it opens its mouth to swallow me up! and how defective my confidence in thee! How weak the flesh, how powerful Satan! If I must put my hope in that which the world calls powerful, I am undone!... The knell is struck,[521] and judgment is pronounced!... O God! O God! O thou, my God! assist me against all the wisdom of the world! Do it: Thou must do it.... Thou alone ... for it is not my work, but Thine. I have nothing to do here; I have nothing to do contending thus with the mighty of the world! I, too, would like to spend tranquil and happy days. But the cause is Thine: and it is just and everlasting! O Lord! be my help! Faithful God, immutable God! I trust not in any man. That were vain. All that is of man vacillates! All that comes of man gives way. O God, O God, dost thou not hear?... My God! art thou dead?... No, thou canst not die! Thou only hidest Thyself. Thou hast chosen me for this work. I know it! Act, then, O God!... Stand by my side, for the sake of thy well beloved Son Jesus Christ, who is my defence, my buckler, and my fortress." [519] "Also sollen wir den Sohn Gottes als Gorgonia Haupt..." (L. Op. (W.) xxii, p. 1659.) [520] L. Op. (L.) xvii, p. 589. [521] "Die Glocke ist schon gegossen." (Ibid.) The affair is decided.