Thomas Brooks on the enduring nature of godly sorrow (Works, Vol. 3, pp. 394-395):
Godly sorrow is a lasting sorrow, it is a durable sorrow. As long as a Christian continues sinning, he cannot but continue mourning. David’s sins were always before him, Ps. 51:3, though his Absalom nor his Bathsheba were not ever before him. Godly sorrow will every day follow sin hard at heels. Look, as a wicked man, in respect of his desire and will to sin, would sin for ever, if he should live for ever; so I may say, if a godly man should live for ever, he would sorrow for ever. After Paul had been converted many years, some think fourteen, you shall find him a-mourning and lamenting over his sins, Rom. 7. An ingenuous child will never cease mourning, till he ceases from offending an indulgent father. Though sin and godly sorrow were never born together, yet whilst a believer lives in this world, they must live together. And indeed holy joy and godly sorrow are no ways inconsistent, Ps. 2:11; yea, a godly man’s eyes are always fullest of tears, when his heart is fullest of holy joy, &c. A man may go joying and mourning to his grave, yea, to heaven, at the same time . . . . Repentance is a grace, and must have its daily operation as well as other graces; witness the very covenant of grace itself: Ezek. 16:62, 63, ‘I will establish my covenant with thee; and thou shalt know that I am the Lord: that thou mayest remember, and be confounded, and never open thy mouth any more because of thy shame, when I am pacified towards thee for all that thou hast done.’ Certainly a true penitent can no more satisfy himself with one act of repentance, than he can satisfy himself with one act of faith, or with one act of hope, or with one act of love, or with one act of humility, or with one act of patience, or with one act of self-denial. Godly sorrow is a gospel grace that will live and last as well and as long as other graces; it is a spring that in this life can never be drawn dry.