What was stated in that thread, and I think, generally agreed upon, was that spirituality does develop, evolve. There are some major stages to spiritual unfolding. One can believe in spirit, have faith in spirit, directly experience spirit and become spirit.
Belief is the earliest and perhaps most common orientation to spirit. As belief requires images, symbols and concepts it clearly originates in the mental and, like the mental, it goes through several transitional stages.
Magic belief is egocentric in that there is a belief that the individual self can affect the physical world and other people. Voodoo and sympathetic magic (pointing the bone in Australian Aboriginal culture) fall into this category.
Then comes mythic belief. This is socio or ethnocentric, different people have different myths that are mutually exclusive. Here spiritual intuitions are invested in a physically disembodied god (or goddess) who has ultimate power over humanity. I think we can safely assume that there are some who post here who would fit in that group.
From here we go to rational belief that attempts to demythologise the belief structure and portray the deity, not as an anthropomorphic entity, but as an ultimate ground of being. Harvey comes to mindbut oft times he seems to have a foot in both camps.
The next stage is a transrational or vision-logic belief. A characteristic of vision-logic is the ability to conceptualize and compare different perspectives or points of view. This stage could be summed up as the Centauric Self (an integration of the body/mind). It is a worldcentric outlook that encompasses rational ethics, perspectivism, postconventional morality, mutual understanding and so on.
Bear in mind I am referring here to the spiritual. An individual could have a worldcentric outlook when it comes to, say, environmental issues but be firmly entrenched in a mythical belief system like christianity.
When belief loses its power to compel, which being mental, it will, faith will takeover. Years and years can be spent trying hard with mythic beliefs, which may give some meaning in a translative sense but not much happens in the way of spiritual transformation. In fact the beliefs become beset by rational arguments and doubts. Mere beliefs are spiritual empty calories, faith, in the short term, can provide some real nutrition. Faith will soldier on when belief becomes unbelievable for faith hears the call, albeit faintly, of some sense of a higher reality that is beyond belief.
Direct experience usually comes in the form of some peak experience. These are usually brief, often intense, sometimes unbidden, perhaps life changing glimpses into some aspect ones own higher potential. (Maslow researched and wrote extensively on this topic in the 70s). Most people remain at the level of belief or faith (usually mythical at that) but occasionally some will have a strong peak experience. This can have mixed results. If the person is firmly entrenched in the concrete-literal mythic level such an experience can result in a reborn fundamentalist: their particular mythic god-figure is the only one that can save the entire world. They will burn your body to save your soul. If the one having this does not translate this downward into a lower level it can open the door for such experiences to be more constant and enduring. This will not happen spontaneously, it will usually require many years of intense spiritual practice.
Becoming spiritthat I think is another issue and perhaps another post.
I obviously would concur some focus is required in order to define higher aspects. Christians I have spoken with argue that god alone is the reason for these higher aspects. I believe these higher aspects are aspects of humanity - those aspects that have lead, in the past, to people such as the Buddha, Christ, Ghandi, Nelson Mandela, Martin Luther King and other saints of society. The believer in the mythic will say that god has guided all these, or, in the case of Christ, were god.
If it was the higher aspects alone we were talking about I could (almost) comfortably call it god. But god is not just this. God, as Christians tell us, is endowed with a whole heap of other functions and qualities that I do not and cannot acknowledge.
Meanwhile spiritual evolution will continue unabated despite the best, and no doubt admirably motivated, efforts of the believers of the mythic to encourage us all to be just like them.

