The Westminster Confession of Faith (VII, 2) describes the covenant of works as follows: The first covenant made with man was a covenant of works, wherein life was promised to Adam, and in him to his posterity, upon condition of perfect and personal obedience. This language can be understood in two different ways. 1) It may mean simply that as long as Adam continued in obedience to the commandment of God regarding the tree of the knowledge of good and evil, he would continue to live happily with God in the garden prepared for him and Eve., doing the work God had given him to do. 2) Many today take it to mean that God promised Adam at least a confirmation in the state of perfection after a period of probation. In the first the possibility of a fall into sin would continue. In the second, after the period of probation had passed, such a possibility would no longer exist.
I do not know what the original framers of the Westminster Standards meant, but I believe that the second interpretation of their words is unsupported by Scripture and, in fact, runs counter to important Scriptural teaching.
Regarding the lack of support in Scripture, the account of Adam’s creation and of God’s words to Adam regarding the trees do not contain any promise of a confirmation of life or mention of a period of probation. The idea of a period of probation seems to derive not from Scripture itself but from the positing of a confirmation of life. If God promised such a thing, then it must follow that a certain amount of time would pass before the promise was fulfilled. If there is no promise of a confirmation of life, the need for the period of probation disappears.
Furthermore, there is only one passage that might describe the threat of Genesis 2:17 and its implicit promise of life as a covenant. It is Hosea 6:7: But like men they transgressed the covenant. The word “men” could be translated as “Adam,” and most recent translations do translate it that way. The Septuagint does not. The verse might mean only that breaking covenants is typical of man in his fallen state. Genesis 2 does not mention the word covenant and there is no oath or other ceremony of ratification such as Biblical covenants require. The word of God in Genesis 2:16–17 contains three elements: permission to eat of every tree of the garden, a command not to eat of one tree, and a threat of death upon disobedience to the command. The promise of life is implicit, not spoken.
I do not object strenuously to calling these words a covenant, but it must be admitted 1) that there is no expressed promise here, and 2) that there are many promises of God throughout the Scriptures that we do not call covenants (e.g. Gen. 19:21–22, Matt. 4:19). We do not call them covenants because there is no oath taking or other ceremony of confirmation.
However, the most important objection to the idea of a confirmation of life upon successful passage of a period of probation is that it implies the idea of merit. Obedience to the command would have earned for Adam something better than he had received in the beginning. Not only do the Scriptures teach that obedience cannot merit (Luke 17:10), but the implication of this idea of merit is that the law can give something which lies outside its scope: it can give a better life than the life it defines.
The law defines the sphere of life. God says, “Do it and live.” As long as we do it, we remain in the sphere of life. When we transgress, when we go beyond the boundaries it defines, we die. The law is powerless to bring us back to life or to advance us to something better. It can kill. It cannot give life, or improve the life it defines. Only the grace of God in Christ can restore life or improve on the life that the law defines. What the law could not do… God did (Rom. 8:3).
This is also why we should not speak of our Lord Jesus Christ as keeping the covenant of works for us. If He had done that, He would only have restored to us what Adam lost. But He is the Lord from heaven, the life-giving spirit, the heavenly man who raises us to a heavenly life (1 Cor. 15:45–49). He became sin for us, completed atonement, and received life and the Spirit in abundant measure because He had done more than obey the law. He had also suffered its curse and penalty to the last bitter drop and conquered death itself. By such power He could give more than Adam’s life; He gives eternal heavenly life, life which, by definition, cannot be lost and is far more glorious than Adam’s life in the garden.
If we must speak of a covenant with Adam, we should call it the covenant of creation rather than the covenant of works. Works imply merit. Even without Adam’s fall and in perfect obedience we have no merit, only a remaining in the sphere of life which the law defines.