Man who has eaten from the eitz ha-da'at assuming this premise can no longer be tolerated in Gan Eden where the rewards await those who eat what and when they are told. Like his placement in Gan Eden, man's expulsion is described twice to accent the repudiation of both aspects of his charter. In pasuk 23 man is sent out to work the ground he consists of - man's life now revolves around the dirt aspect of his makeup. In pasuk 24, the Torah repeats man's expulsion - this time to stress that now keruvim with a revolving sword protect Gan Eden. The Gan Eden narrative redefines the world as we know it.
Negatives are very often the result of man's misguided actions.
God's commandments must be obeyed without question. Any attempt to outsmart them is doomed to fail. Although perek 4 tells a new story about a new generation, it bears a striking resemblance to the preceding incident. Like Adam, Kayin sins after being warned by God. The world is created to serve man who serves God.