Why didn't Adam and Eve immediately die for their sin (Genesis 3)?

Man was formed in the strength of his manhood, nor were there any influences of decay or any signs of death upon, around, or before him. All was life. But God had proclaimed that in the day of disobedience he should surely die (Gen. 2:17)." We know the true and awful story of the fall: indeed its sad evidences are around and in us all today. But Adam did not expire at once. True it is that death set in, and that in this sense from the moment of his fall he was a dying man; but what did actually happen was that he became an outcast from the presence of God. This was "death" in a most terrible aspect. The bodily act of dying was but a small thing, compared to the spiritual death, the separation from God, which was beyond measure appalling, as it surely ends in judgment everlasting.

The first use of the word death in Genesis 2 and 3 clearly bears this out. God threatened Adam with death on the day of his disobedience. Adam disobeyed and lived on to the age of nine hundred and thirty years. Was it, then, an idle threat? Not at all. The day he sinned he died, in the first sense of the word, i.e. he became totally separated and estranged from his Maker, "dead in sins." His physical death was deferred inasmuch as the Lord brought death that day upon some other denizen or denizens of the garden and clothed the guilty sinners with their skins. Centuries after, physical death supervened. Adam then passed out of all touch with this world, but he exists as regards God. As the Lord Himself said, "all live to Him" (Luke 20:38).

Moreover, he was warned as to the consequence of disobedience. If he acquired the knowledge of good and evil by disobedience, he would be unable to perform the good because enslaved by the evil. This would bring him under the power of death immediately. As we discover in the next chapter, he would not at once suffer the death of the body, which involves the dissolution of existing personality by separating the spiritual part from the material part of man. But he would at once suffer complete severance spiritually and morally from God, his Creator, which is death in its more intense form. In that sense he would die the very day in which he ate of the forbidden tree. To obey the one prohibition was his responsibility.

The curse was then pronounced upon the serpent and the earth was cursed on account of man and sentence pronounced upon the man and the woman, the evidences of all this are about us. The sentence "dying thou shalt die," that is physical death, the wages of sin, was not executed at once.

Then came the prohibition, not to eat of the tree of the knowledge of good and evil. In the day that Adam should eat of it he would surely die. Not that he should die the very day he partook of the fruit of the tree, but that the process of death would then begin in his body, and death would inevitably ensue.

But, second, note that death did fall in the garden on the very day of Adam's sin. Not on him personally but on some innocent victim, or victims, out of whose skins the Lord God made clothing for the guilty pair. Thus early was testimony given in a typical way to the fact of death as the wages of sin and also to the efficacy of a substitutionary sacrifice.

Our first parents took of the tree of the knowledge of good and evil, and thus disobeyed God’s prohibition. The penalty was death—“in the day that thou eatest thereof thou shalt surely die” (Gen. 2:17). The marginal reading is “HEB. dying thou shalt die,” that is to say, the process of death began the moment sin was committed, just as if you plucked a flower in your garden, that moment it begins to die. You may put it in water and retard the process, but it is true of that flower “dying it shall die”—surely and slowly, death ensues.

"In the day that thou eatest thereof thou shalt surely die" is defined so clearly, in the Lord's words to fallen Adam, as to put its meaning, one would think, beyond serious question. "In the sweat of thy face shalt thou eat bread, till thou return unto the ground; for out of it wast thou taken; for dust thou art, and unto dust shalt thou return."

Nor can spiritual death, or "death in trespasses and sins," be possibly what God speaks of in His threatening to Adam. This is indeed the spiritual state which is the result of the fall but the moral state of a criminal is a very different thing from the judgment upon the criminal. Man's depravity is what he is condemned for, not what he is sentenced to; and these things cannot be synonymous. "Dust thou art, and unto dust shalt thou return" is thus the only possible, as it is the divinely given, interpretation of the announcement, "In the day thou eatest thereof thou shalt surely die."

Yet it is quite true, and to be pressed, that this death, coming not only upon the first sinners, but upon all their posterity, — and surely by no mere arbitrary decree on God's part, — marks the changed relation to Him of the now fallen creature. Everywhere does Scripture recognize this, and in God's ordinances for his chosen people of old it comes fully out. Death is associated ever with uncleanness and defilement. If a man die in a tent, all that come into the tent, and all that is in the tent, are unclean seven days. Every one touching a dead body, a bone, or a grave, is similarly defiled. Nor must we look at this as merely symbolic teaching. The psalm of the wilderness is plain enough in its doctrine here: "For all our days are passed away in Thy wrath; we spend our years as a tale that is told. The days of our years are threescore years and ten; and if by reason of strength they be fourscore years, yet is their strength labor and sorrow; for it is soon cut off, and we fly away. Who knoweth the power of Thine anger? even according to Thy fear, so is Thy wrath." (Ps. 90:9–11.)

At the beginning we get the strongest expression of the holiness and righteousness of God — "In the day that thou eatest thereof thou shalt surely die." Here the Lord attaches to the first commission of evil nothing less than complete separation from Himself; for He is the living God. As such He had just shown Himself; He had just become the source of all that in that moment was surrounding Him in earth, air, and seas; He was the living and life-giving God, and, therefore, a state of death was a state of separation from Him. And this state is announced to be the sure and immediate doom of the creature on the moment of his commission of evil. What a strong assertion, thus, at the very outset, of the purity of God, of the great truth that "God is light, and in Him is no darkness at all;" the creature that becomes a child of evil, a child of darkness, must at once be an exile from Him — "In the day that thou eatest thereof thou shalt surely die."