1. Sin is either the first sin or the result of it.
2. The first sin is the disobedience of the first parents, by which they transgressed God’s prohibition concerning the tree of the knowledge of good and evil.
I. The cause of the transgression of Adam and Eve was neither God nor a decree of God, nor the withholding of any special grace, nor the permission to fall, nor any naturally incited motive, nor the providential government of the fall itself.
It was not God, because he had most strictly forbidden the eating of the fruit of that tree. It was not his decree, because that carries only an immutable, not a coercive necessity, nor does it lead anyone toward sin. It was not the withholding of some special grace by which man might have remained innocent, for there was no obligation to give even the grace that God did give man; he received, in fact, the ability to act as he willed, although not that of willing as he could. It was not any naturally incited motive, for a motive in itself is not sin. It was not the providential government of the fall, for to bring good out of evil is to be the source of good rather than of evil.
II. God both did, and did not, will the first sin. He did not will, in so far as it is sin, but he willed and decreed it, in so far as it is a means of revealing his glory, mercy, and justice.
III. The immediate cause of original sin was the instigation and persuasion of that old serpent, the devil.
IV. Its antecedent cause was the will of man, which by itself was indifferent toward good and evil, but, when convinced by Satan, was turned toward evil.
V. There are five stages of the fall, by which man fell from God one step at a time, not all at once: (1) Thoughtlessness and meddlesomeness when Eve conversed with the serpent in her husband’s absence; ( 2 ) unbelief, as little by little she began to agree with the lies of Satan, who called into doubt the goodness of God toward man, so that she distrusted God; (3) desire for the forbidden fruit and for divine glory; (4) the deed itself; ( 5 ) the temptation of Adam and the arousing of undisciplined desire also in him.
VI. If all the aspects [pars] of this sin are taken into account, it is rightly called transgression of the entire natural law. Man sinned by unbelief, distrust, ingratitude, and idolatry, as he fell from God and set about making an idol of himself. He also sinned by despising God’s word, by rebellion, homicide, and intemperance, by the secret taking of what was not his without God’s permission, by assent to false statements, and finally by the desire for higher dignity, indeed, for the dignity that belongs only to God. Whence it is too narrow a definition to call this sin intemperance, ambition, or pride.
Johannes Wollebius, “Compendium Theologiae Christianae,” in John W. Beardslee III, Reformed Dogmatics (Grand Rapids, Michigan: Baker, 1977), 67-68.