Genesis 3:22-24 is, I think, a very key passage in terms of understanding our relationship to the power of God and why as spiritual beings we are here in human form. "Then the LORD God said, ’Behold, the man has become like one of us, knowing good and evil; and now, lest he put forth his hand and take also of the tree of life, and eat, and live forever—therefore the LORD God sent him forth from the garden of Eden, to till the ground from which he was taken. He drove out the man; and at the east of the garden of Eden he placed the cherubim, and a flaming sword which turned every way, to guard the way to the tree of life" (RSV).
At an earlier stage in our spiritual understanding, we believed that we were exiled to Earth as punishment by an angry and punishing God. From that perspective, this passage made perfect sense. But the teachings and example of Jesus Christ have helped us to move beyond that level of belief, to realize that we are not caught up in a battle between opposing forces of good and evil. God is an energy of omnipotence, and omnipresence—all powerful and everywhere present. So there can’t be an opposing power that is not God, nor a place where God is absent. So the belief in separation—in a "Fall" from grace—is a false belief, a limited belief, and we must move beyond and above it to clearly understand our purpose.
We come to see that "leaving the garden" is a choice that we freely make, and that the loving power of God supports us in that choice. The negatives described in Genesis—the pain of childbirth, the toiling for food—are not punishment; they are inevitable consequences of the choice we have made. We enter into a dualistic experience so that we can be creative as our Source is creative. In the process we lose sight of our true spiritual identity and creative power, and we move through the sometimes painful process of rediscovering it and learning how to express it in our human lives—so that by making choices that affirm love and dissolve ignorance we can bring this mortal experience into alignment with the energy of the divine. So we experience duality in order to rediscover our Oneness and then make the creative choices that bring that Oneness into expression.
The tree of life is sort of a "bookend" symbol in the Bible. It appears early in the first book and reappears again at the conclusion of the final book, the Revelation to John. Here, in Genesis, God is not punishing us but rather protecting us. If we eat of the tree of life too soon—before we have completed our spiritual purpose—we will be forever locked in an incomplete and limited state of consciousness. So for our own safety we are kept away. Once we have achieved Christ consciousness, and through that consciousness have created the kingdom of heaven described in Revelation 21, then the tree of life is freely available, "and the leaves of the tree were for the healing of the nations" (Rev. 22:2).
As for the serpent, what’s important to remember is that it, too, is a creation of God and thus an agent in the great divine intention. It speaks directly to the innate creative urge that is an integral part of Eve’s spiritual identity—and of ours—urging us to trust that urge and follow it, taking the risk of moving beyond mere acceptance and obedience to begin the process of discovery that will allow us to become clear channels for the creative power of God that is our true identity.