Effectiveness rather than philosophical or historical demonstration has always been the hallmark of a successful religion.
Religion was a matter of cult and ritual rather than ideas; it was based on emotion, not on ideology or consciously adopted theory. This is not an unfamiliar attitude today: many of the people who attend religious services in our own society are not interested in theology, want nothing too exotic and dislike the idea of change. They find that the established rituals provide them with a link with tradition and give them a sense of security.
Human beings are aware that something is wrong with their condition; they feel at odds with themselves and others, out of touch with their inner nature and disoriented. Conflict and lack of simplicity seem to characterize our existence. Yet we are constantly seeking to unite the multiplicity of phenomena and reduce them to some ordered whole. To find the underlying truth of reality, the soul must refashion itself, undergo a period of purification and engage in contemplation. It will have to look beyond the cosmos, beyond the sensible world and even beyond the limitations of the intellect to see into the heart of reality. This will not be an ascent to a reality outside ourselves, however, but a descent into the deepest recesses of the mind. It is, so to speak, a climb inward.
A God who is in some mysterious way a person and who takes an active part in human history lays himself open to criticism. It is all too easy to make this God a larger-than-life tyrant or judge and make him fulfill our expectations. We can turn God into a Republican or a socialist, a racist or a revolutionary according to our personal views. The danger of this has led some to see a personal God as an unreligious idea, because it simply embeds us in our own prejudice and makes our human ideas absolute.
The ultimate failure of a rational deity has something important to tell us about the nature of religious truth.
A personal God can become a grave liability. He can be a mere idol carved in our own image, a projection of our limited needs, fears and desires. We can assume that he loves what we love and hates what we hate, endorsing our prejudices instead of compelling us to transcend them. Instead of inspiring the compassion that should characterize all advanced religion, he can encourage us to judge, condemn and marginalize.
The mystical experience of God has certain characteristics that are common to all faiths. It is a subjective experience that involves an interior journey, not a perception of an objective fact outside the self; it is undertaken through the image-making part of the mind--often called the imagination--rather than through the more cerebral, logical faculty.
Today many people in the West would be dismayed if a leading theologian suggested that God was in some profound sense a product of the imagination. Yet it should be obvious that the imagination is the chief religious faculty. Human beings are the only animals who have the capacity to envisage something that is not present or something that does not yet exist but which is merely possible. The imagination has thus been the cause of our major achievements in science and technology as well as in art and religion. The idea of God, however it is defined, is perhaps the prime example of an absent reality which, despite its inbuilt problems, has continued to inspire men and women for thousands of years. As in art, the most effective religious symbols are those informed by an intelligent knowledge and understanding of the human condition.