It is a state or condition of our moral nature that is the result of what we have done. Moral depravity is a developed habit of life, a tendency to keep on doing what we have been doing. Every wrong action deepens the ruts of our depravity until we develop mighty monsters of bondage, either amiable or degraded as men view things, that require ever-increasing energy of will to counteract. Pelagius merely conceded, that Adam, by his disobedience, set a bad example, which exerts a more or less injurious influence upon his posterity. He was also inclined to admit an increasing corruption of mankind, though he ascribed it solely to the habit of evil, which grows in power the longer it works and the farther it spreads.
Man is born both without virtue and without vice, but with the capacity for either.
The universality of sin must be ascribed to the power of evil example and evil custom. To maintain otherwise would be to impute evil to the Creator. Thus Caelestius maintained that sin was something committed by man after birth and was a personal act of the will, independent of any antecedent evil propensity. The only moral corruption possible, according to this view, is the result of repeated sin and is therefore only to be found in adults. Paul makes mention of this situation and the impossibility of fighting it in our own strength in the seventh chapter of Romans.