“Jewish, Christian, and Muslim theologians have insisted for centuries that God does not exist and that there is 'nothing' out there; in making these assertions, their aim was not to deny the reality of God but to safeguard God's transcendence.” ― Karen Armstrong, The Case for God
In her book, Karen Armstrong makes the case that originally all religions practiced an apophatic theology--a theology in which God is only considered in negation. Underlying this view is the belief that God cannot be adequately described through language. This is why, as stated above, a person can worship God without saying that God exists. After all, existence applies to ordinary things that are defined relatively and therefore must change, and one purpose of religion is to connect with a reality that does not possess this nature. Originally the apophatic view was so important that any attempts to describe God affirmatively were ignored or considered blasphemous. However, this attitude has changed over the course of history. In Armstrong's book, she traces this shift and shows how we arrived at the problematic state of modern thought, in which people don't seem to recognize any problem in defining what God or reality is supposed to be.
The culprit, unexpectedly, is reason. To summary Armstrong's book, as Christian scholasticism gave rise to the modern study of natural philosophy, the practice of religion became increasingly intellectual and decreasingly mythical. Instead of searching for personal meaning in our emotional responses to religious stories and practices, we started searching for objective meaning in the empirical world. Science was born as a new religious practice. The Deists, like Isaac Newton, sought to understand God by understanding the principles underlying God's works. Even though we tend to think of science and religion in conflict, in their modern forms they both express the same impulse to understand reality in terms of something external. This focus on something "out there" makes them more similar than either might care to admit.
For examples of the abiding unity between science and religion, look at the underlying intentions of two areas of cutting-edge research: the intense mapping and analysis of the cosmic microwave background radiation is a recent development in the ancient search for a first cause, while the search for the Higgs boson reflects a deep-seated belief in the concreteness of reality.
I'm not trying to say that these lines of research will fail to turn up definite results, but the meaning of those results is open to interpretation. When we look for answers we tend to find them; the Void can't fail to respond logically to our logical actions upon it. The question is whether those answers reflect a true understanding of reality, or whether the results of a particle smashing experiment simply reveal one more face of the big illusion.
In parallel, the same interpretation can apply to the modern practice of religion in which God is defined using words. Do those practices reflect a true understanding of reality, or are they a big defense mechanism to make the ego feel comfortable in an uncertain world? This is not a criticism of religion only--it is a serious question for atheists as well.
One problem with concrete language is that it never agrees completely with our shifting and relative reality, so it leads to absurdities that alienate. It can alienate other people, the way atheist biologists and fundamentalist Christians alienate one another. It can alienate ourselves, the way our expectations and ideals from yesterday make us feel inadequate today. Letting go of fixed notions of reality--the essence of the apophatic tradition--is the key to being flexible and forgiving in our relationships with people (including ourselves) who have varying beliefs and subtlety of understanding. That, in turn, is a major step toward being happy.
The capacity for this type of approach is innate to every religion, but it's hard to find these days. After a spirited search, I ended up practicing Buddhism because the Buddha's teachings are so clearly focused on just this issue. The Buddha used many words to explain to people the shortcomings of words. In this regard, his teachings are helpful in any context, whether it's another religion, atheism, science, or academics. Learning from these teachings is not inherently a magical or mystical experience; it doesn't even have to be a religious experience as we've come to think of it; it can simply be a process of removing the misinterpretations that prevent happiness.