This is not the time to talk about religion in a thoroughly analytical way; which means that it is exactly the time that we must do so. It is a basic human rule: subjects that the culture makes off-limit or excessively stylized are exactly the subjects in greatest need of cold-eyed examination. The “God” religions and the rejections of all things religious as with Christopher Hitchens seem nearly equally misguided to me.
The first thing that we need to understand is that religion and spirituality have always been a vital -- even defining -- part of human culture. The second thing is that institutional religion -- what we usually mean when the use the word -- has taken on social/cultural designs quite different from the roles that religion and spirit have long served in human life. The third thing is that religion has less to do with God and more to do with prescriptions for behavior. This is easily seen in such assertions as, "if you act in that way, then you must not believe in God." Such a statement is a condemnation of an action; the strength or nature of belief can't be known, so this is only a strong statement of the speaker’s belief that the action is wrong.
Religion is mostly about right and wrong. Spirituality is about the feelings of attachment to the whole universe with all its powers, mysteries and possibilities. The two need each other and humans require them both, but the confusion of the two has, for a long time, been a source of great misery. When belief takes the form: "my feelings of purpose and attachment require that I act in this way," religion and spirit are combining in a long successful and natural way. Of course, there are issues and adjustments to be made, but nothing like when the belief takes the form, "my feelings of purpose and attachment require that you act in this way." This statement, too, has a long history, very often with bloodletting in it.
But if the right and wrong of specific actions could be avoided, people of all religious traditions could commune easily on the pleasures and terrors of the spiritual: life, death, meaning, hope. Religious wars are fought over whether to “believe in” a cross or a star, not over the universal sense of the possible.
Part of the design of religion is to give great force to prescriptions of right and wrong. By making the spiritual feelings of acceptance and value conditional on following the rules, by making the spirit a property of the particular religious institution, the ordinary person is said to only be able to obtain the pleasures and protections of the spirit by being a member of the Holy Order of the Natural True Believers. This allows the spiritual power of the prescriptions of right and wrong to be controlled by religion, more especially institutional religion. When spirit is absorbed by the institution and taken away from the person as an essential and personal ingredient of their life, the "church" is transformed into a political tool, first and foremost intent on its own protection as an institution and only secondarily the custodian of souls.
People of different religious traditions cannot meet on the level ground of spiritual communion when values are controlled by prescription -- the spirit starves. In this circumstance belief must become fanatical to drown out both the questions from within and dangerous differences from without. And true believers become more and more easily moved by the unscrupulous who are drawn to use them as a source of power.
This has happened over and over, accompanied by great tragedy, to many religious institutions in our history, with the greatest tragedy of all being the loss of the personal spirit. In our hundred and fifty thousand years on earth as Homo sapiens, it is the fulfillment of the personal spirit -- the feelings of purpose and attachment to other humans, to all life and to the universe itself -- that has been the vital force in human existence, not our wars or our buildings or our science. And it is only that melding of religion as a powerful force for prescribing behavior and an independently powerful spirit that will give us a future in what are certain to be trying times ahead.