But still, why do they manifest to some of us and not to all of us?
The answer is and likely will remain a mystery, but I can think of several possibilities, some flattering to the person having the experience, and some not.
One thing I am pretty sure of: those of us to whom deities and spirits manifest are not necessarily more advanced spiritually. Or if they are, they do not always maintain any noticeable advancement, and get caught up in personal power seeking. At the Umbanda temple I attended for many years, incorporative trance is more central than even in Gardnerian Wicca. Even so some people sought an encounter yet never had one, while others did. Eventual success often took months, or even years. Yet I could find no correlation between these experiences and the person's spiritual or moral qualities.
Following a spiritual path, growing in wisdom, and encountering deities seem to be different phenomena.
Over the past few years I discovered that not only had many Pagans not had such experiences, some even called themselves "atheists." In Christian terms perhaps we are all "atheists" because we do not believe in the reality of their deity as the lord and creator of everything. But some meant the term more generally, in part at least because they had never had an encounter with a deity.
For them honoring and celebrating the world as the center of more-than-human value and beauty was enough to become a part of the Pagan community. It is certainly enough for me to regard them as my equal within our community. And yet, it's perplexing that experiences so powerful and relatively common to others and myself are unknown to others who practice broadly the same path we do.
It seems to me there are two ways to be a Pagan atheist, both understandable and worthy of respect by those of us who are not. Honoring the world, seeking to live in harmony with it, delighting in its beauty, exulting in the ecstasy of sexuality and the unspeakable intensity of a loving connection are enough to give a person a rich and meaningful life. Our traditions and celebrations fit wonderfully well within such an approach, and provide a way for people to live in this fashion in community with others. If a person is sensitive enough to these dimensions of life, in a sense the Gods are not needed.
At the same time, for me and for many others I know, within this society getting involved deeply with deities makes life very complex. If a person has a family, a traditional career, and so on, he or she might choose not to pursue this dimension of the sacred, and be wise in doing so. Unless a deity decides to make their existence unmistakable, such a person can be quite content to leave well enough alone. They may not consider themselves atheists, but they will not be drawn to encounter the Gods. After all, our traditions do not claim the need for or to be the route to "salvation."
One of the wonderful things about our religion is that we do not care very much what a person believes. If they come and join us in what we do because for whatever reason it speaks to them, that is enough to make them one of us. Intellectually I cannot understand "Christopagans." But there are many such and when push comes to shove, their theology, if they have one, is between themselves and their Gods. Do they love the earth? Do they celebrate the cycles of the seasons? The phases of the moon and what it symbolizes? Do they honor the Divine Feminine and Masculine in some way harmonious with my approach? Is the chemistry between us good? If so, we can circle together amicably. The same holds true for those who do not believe in "the Gods" at all.
But the Gods do exist, and some who have not experienced them would like to do so. What follows is for them to consider.
Encouraging Close Encounters
If you have not encountered a deity, or even an entity from the spirit world, ones that by contemporary secular standards cannot exist, how might you?
My initial encounters and most of my strongest encounters with deities have all been in ritual settings where they have been deliberately invoked. These have been public Sabbats, intimate Esbats, or at a Buddhist temple. In my experience this suggests to me that even if the sacred is everywhere, ritual space is a way to concentrate that energy or make it easier to manifest to us through the mental static of our daily lives and concerns. A ritual within an established tradition can tune in to the sacred as it manifests within that tradition.
In addition, doing ritual with others has been a constant in my experience of the strongest encounters with deities. I have encountered deities when alone, but not as strong and not until after having made an initial encounter within a formal, ritual space with a group of like-minded people.