There are two definitions of Spiritual evolution
One, to quote from the Wikipedia page on the subject which I co-authored, is the Cosmological or Philosophical perspective, which is
the philosophical, theological, esoteric or spiritual idea that nature and human beings and/or human culture evolve along a predetermined cosmological pattern or ascent, or in accordance with certain pre-determined potentials.
Within this broad definition, theories of spiritual evolution are very diverse. They may be cosmological (describing existence at large), personal (describing the development of the individual), or both. They can be holistic (holding that higher realities emerge from and are not reducible to the lower), idealist (holding that reality is primarily mental or spiritual) or nondual (holding that there is no ultimate distinction between mental and physical reality). All of them can be considered to be teleological to a greater or lesser degree.
Philosophers, scientists, and educators that have proposed theories of spiritual evolution include Nader Angha, Schelling, Hegel, Max Théon, Henri Bergson, Sri Aurobindo, Jean Gebser, Pierre Teilhard de Chardin, Arthur M. Young, Edward Haskell, E. F. Schumacher, Erich Jantsch, Clare W. Graves, Alfred North Whitehead, Terrence McKenna, P.R. Sarkar, Spiral Dynamics, and Ken Wilber. Thesy tend (for the most part) to be non-materialistic or non-reductionistic.
The other (which sometimes overlaps with the above) is the occult perspective of the evolution of the immanent Divine Principle, the Higher Self or Soul, through successive lifetimes. This is explained by H. P. Blavatsky(the Higher Manas or Immortal Ego in Theosophy), Sri Aurobindo (the Psychic Being), and elsewhere. Because this assumes reincarnation as an integral fact, these ideas are less likely to be embraced by the mainstream.
Spiritual evolution – some diagrams
|From The Future of Mankind a detailed online resource of information produced by New Age contactee Billy Meier – original url||From a large New Age site, Image Gallery – huge number of illustrations original url of above graphic (found on this page)|
The above are two diagrams or interpretations of spiritual evolution, selected more or less at random from the web. One (left) refers to a transcendentalist ascent through a number of specifically defined stages, in keeping with the Theosophical and New Age worldview. The same idea of ascent to more spiritual and transcendent states, but without reincarnation, is also found in Anglo-American Spiritualism, 19th century occultism, and channelled communications like the Oahspe Book, and Early (pre-Esoteric Buddhism/Secret Doctrine) Theosophy. This idea of an ascent to progressively more transcendent states is the opposite of the this worldly evolutionary transformation taught by Lurianic/Hassidic Kabbalah and Aurobindonian Integral philosophy.
The other (right) diagram is cyclic and highly detailed, and represents an elaborate cosmology beautifully portrayed in terms of cosmic diagrams. This idea of a cosmic cycle of fall and ascent, or involution and evolution, is incorporated into a spiral. The theme of spiral evolution is also found in the teachings of the Danish mystic Martinus, and in Spiral Dynamics.