From Parochial and Plain Sermons
by Venerable John Henry Newman:

When Zacchaeus gave half his goods to the poor, and restored fourfold what he had wrongfully obtained, this was an act of repentance in one who would fain undo the past. They are acts of a mind, lingering and engaged in the past, as hope is engaged in contemplating the future. It is common enough at present to speak lightly of the past, as if it was past and could not be helped, as if we could not reverse the past. We cannot literally reverse it; yet surely instances such as the foregoing are the acts of persons who would if they could; who, as it were, are trying to do so, and in a manner doing so from the intense feeling of their hearts. Regret, vexation, sorrow, such feelings seem to this busy, practical, unspiritual generation as idle; as something despicable and unmanly,—just as tears may be. And many men think it religious to say that such feelings argue a want of faith in Christ's merits. They are unbelieving, they are irrational, if they are nothing more than remorse, bitterness, gloom, and despondency. Such is "the sorrow of the world" which "worketh death." Yet there is a "godly sorrow" also; a positive sorrowing for sin, and a deprecation of its consequences, and that quite distinct from faith or amendment; and this, so far from being a barren sorrow, "worketh," as the Apostle assures us, "repentance to salvation, not to be repented of." "Behold this selfsame thing," continues the Apostle to the Corinthians, "that ye sorrowed after a godly sort, what carefulness it wrought in you, yea what clearing of yourselves, yea what indignation, yea what fear, yea what vehement desire, yea what zeal, yea what revenge! In all things ye have approved yourselves to be clear in this matter." [2 Cor. vii. 10, 11.] Faith, then, neither is repentance, nor stands instead of it.