Repentance is necessary for MORAL people
Exerpt from Thomas Watson's, The Doctrine of Repentance
These [moral people] have no visible spots on them. They are free from gross sin, and one would think they had nothing to do with the business of repentance. They are so good, that they scorn God's offer of mercy. Indeed these are often in the worst condition: these are they who think they need no repentance (Luke 15:7). Their morality undoes them. They make a "savior" of it, and so on this rock they suffer shipwreck. Morality shoots short of heaven. It is only nature refined. A moral man is but old Adam dressed in fine clothes. The king's image counterfeited and stamped upon brass will not go current. The moral person seems to have the image of Godâ€”but he is only brass metal, which will never pass for current. Morality is insufficient for salvation. Though the life is moralized, the lust may be unmortified. The heart may be full of pride and atheism. Under the fair leaves of a tree, there may be a worm.
I am not saying, repent that you are moralâ€”but that you are no more than moral. Satan entered into the house that had just been swept and garnished (Luke 11:26). This is the emblem of a moral man, who is swept by civility and garnished with common giftsâ€”but is not washed by true repentance. The unclean spirit enters into such a one. If morality were sufficient to salvation, Christ need not have died. The moral man has a fair lampâ€”but it lacks the oil of grace.