The Covenant of Grace
"The man called his wife's name Eve, because she was the mother of all living. And the LORD God made for Adam and for his wife garments of skins and clothed them" (vv. 20-21).
Permanent possession of Eden and its joys was not a given for Adam and Eve, but our first parents had to render obedience to God in order to be accounted worthy of eternal life in the garden before the Lord's face. As such, Adam and Eve were placed under probation in the covenant of works (Gen. 2:15-17). The terms of the probation were particularly important for Adam, as he was humanity's federal head or representative before God. Only by keeping the covenant and by passing the Lord's test would he have merited eternal life. This test was centered on the Tree of Knowledge of Good and Evil (v. 17). Our Creator commanded Adam and Eve not to eat from this tree, and He gave them the fruit of all other trees to eat. The actual fruit is unimportant; the key thing is what the fruit represented, namely, a willingness to continue loving and trusting the Lord. To prove faithful, all our first parents had to do was refrain from eating the forbidden fruit.
Though the forbidden tree was called the Tree of Knowledge of Good and Evil, we should not think that Adam and Eve lacked all knowledge of right and wrong before they ate. Our first parents at least knew that it would be good to obey the Lord and evil to disobey Him, and that is why the temptation was not really for Adam and Eve to gain knowledge they did not already have. In the words of the serpent, the temptation was to become "like God, knowing good and evil"; (3:5, emphasis added). Satan held out to them the possibility that they could become a law unto themselves, autonomous agents who are under no obligation to the Creator. He was tempting them to believe that they could determine right and wrong for themselves, that they need not be subject to God's law.
Yet it is impossible to become free agents who are unaccountable to the Lord, and we must determine right and wrong based on God's revelation. When Adam and Eve ate the fruit, they rejected this principle, and the Lord cursed mankind with difficulty in laboring to produce food and in childbirth. Worst of all, we were cursed with death and barred from the Tree of Life (vv. 17-24). However, the Lord was merciful, and He did not bring death to pass right away. Instead, He gave the first announcement of the covenant of grace, promising to destroy the serpent (v. 15). God also covered Adam and Eve's shame with animal skins (v. 21), ultimately pointing to the day when His Son would crush sin and Satan, and provide the covering of His perfect righteousness for our wickedness and shame.
Coram Deo
Scripture often depicts the Lord as One who is slow to anger and patient with sinners (Ex. 34:6). The fact that He did not destroy Adam and Eve right away after they sinned in Eden is perhaps the best example of this. We are not to presume upon God's kindness, but neither should we think that the Lord is just looking for us to slip up so that He can strike us down. He is eager for us to repent, and that is what we must do when His Holy Spirit convicts us of our sin.