Its oneness is retained in the creation of the Many. The Many returning to the One by evolution first attains oneness and finally Unity. Man is the first conscious being on earth in evolution. This awakening is the process of Knowledge emerging out of Ignorance, Light emerging out of Darkness or Good issuing out of Evil. The soul is one of the four parts of the human being, which consists of body, life, mind and soul.
Soul is the highest part.
Though it is the highest part, it is still a part. Only the being, the embodied being, is the whole of Man. The soul of man detaching itself from mind or other parts enables it to reach the One, which is liberation of the soul. That is not evolution. Evolution is the involved higher consciousness emerging out of its opposite.