This is a summary of what I discovered, so it’s more than just a belief or something I thought out. It’s completely conceptualized in a book called God Speaks by Meher Baba, which added more insights and tied it all together. The book is free as a PDF at: http://www.ambppct.org/meherbaba/BooksByMeherBaba.php
Life is a journey, and the first phase is evolution. It is initiated from a totally unconscious God, as if an infinite Ocean were in a state likened to deep sleep. This unconscious God speaks the First Word "Who am I?” This question disrupts the limitless, undivided, absolute vacuum, and its reverberations create individualized souls, compared to drops or bubbles within the Ocean. By speaking the First Word, God establishes the process of Creation, in which he assumes evolving forms to gain increasing consciousness.
Individuality is the vehicle of this quest. Evolution marks a series of temporary answers to "Who am I?" The soul traverses a multitude of forms, beginning with simple gases and proceeding slowly through inanimate stone and mineral forms. These early evolutionary stages obviously have only the most rudimentary consciousness and cannot provide a satisfactory answer to God's original question.
The original query thus provides a continuing momentum for the drop soul to develop new forms, each with greater consciousness, including the many plant and animal beings. Every evolutionary kingdom reveals new dimensions of consciousness and experience. Each also offers opportunities to gain different kinds of awareness. For example, when the soul identifies itself with varied species of fish, it experiences the world as a creature living in water, conversely, as a bird, it enriches its consciousness by flying through air.
When the drop soul finally evolves to human form, consciousness is fully developed, but an individual is still not aware of the potential of his or her consciousness.
So the original "Who am I?" imperative persists and inaugurates the second phase: reincarnation. Since consciousness is fully developed, there is no longer a need for evolving new forms. The individual's experience, gathered in early stages of evolution, is now humanized and expressed in countless lifetimes. The impulses gained in sub-human forms can play themselves out in the broader context of intelligence, emotions, choices, diverse setting and interactions with people.
But obviously no single lifetime can bear the burden of "humanizing" the entire evolutionary inheritance randomly or simultaneously. There must be a method for re-experiencing the pre-human legacy in manageable segments. The soul thus experiences alternately a series of opposites, organized according to themes. Accordingly, in different lives, the soul becomes male and female, rich and poor, vigorous and weak, beautiful and ugly. Through exploring the potential of these many opposites, one eventually exhausts all possible human identities and, therefore, has fully learned the entire range of human experience.
Here begins the third phase: involution, the process by which the soul returns to the full awareness of the Divine Force, which created him. As Meher Baba puts it, "When the consciousness of the soul is ripe for disentanglement from the gross world (the everyday world of matter and forms), it enters the spiritual path and turns inward."
Like evolution, involution has certain states and stages, consisting of "planes" and "realms." But individuality continues along this spiritual path. In fact, the book, “God Speaks,” quotes the Sufi saying "There are as many ways to God as there are souls...."
Each new plane denotes a state of being that differs from the states that preceded it. The first three planes are within the subtle world or domain of energy, "pran." There follows the fourth plane, the threshold of the mental world, where misuse of great power for personal desire can lead to disintegration of consciousness.
The fifth and sixth planes represent true sainthood, which is understood to be increasing intimacy with God as the Beloved. On the sixth plane, the mind itself becomes the inner eye that sees God everywhere and in everything. "The loving of God and the longing for His union," says Meher Baba "is fully demonstrated in the sixth plane of consciousness."
The seventh plane marks true and lasting freedom. Impressions go. Duality goes. The drops burst and again become the Ocean. God answers his question of "Who am I?" with "I am God." The Infinite has returned to the original starting point. He now knows, however, with full consciousness and full awareness that he was, is and always will be infinite, with infinite bliss, infinite power and infinite knowledge. And, he realizes that the entire journey has been an illusory dream, the purpose of which was the full awakening of his soul.
God Speaks by Meher Baba, free in PDF at: http://www.ambppct.org/meherbaba/BooksByMeherBaba.php