Does God exist? Ostracism or worse is often the punishment for those who dare to ask. Yet metaphysicians are compelled to ask. A theory of what there is would hardly be complete if it said nothing about whether God is. A theory of being qua being would hardly be complete if it said nothing about whether to be is to be in some relation to the divine -- whether, for example, to be is to be created and sustained by God. Moreover, metaphysicians are compelled not only to ask whether God exists, but to treat the answer as anything but a foregone conclusion. Their calling requires them to accept nothing merely on faith, or on authority, or out of inertia or conformity to received opinion. They are to follow the evidence and argument wherever they lead, however unpopular the conclusion. There have been times and places where the punishment for this questioning attitude is death. In our own time there are still such places.

Another hazard for those who would bring evidence and argument to bear on whether God exists is that there are so many ideas of God. According to one idea, the divine nature is personal, as for example in Christianity, Judaism, Islam, and an important strand of Hinduism. According to another idea of God, the divine nature is non-personal, as in a different strand of Hinduism, and in Theravada Buddhism. Some think of God as a Being who rules the world and acts in history. Others deny this, as do Neoplatonists, Stoics, Deists, Buddhists, and Hindus of the Advaita-Vednta school. According to some religions, deity becomes incarnate in the world. According to others it does not. And is the Bible the Word of God, or rather the Qur'an, the Bhagavad Gita, the Book of Mormon, or none of these?

We seem to encounter a hopelessly irreducible plurality of conflicting ideas of God. If asked whether you believe in God, the only reasonable reply may be, "Which one? There are so many." Theists according to one religion may be atheists according to another. It is unsettling to reflect that had we been born in another part of the world, our religion would probably have been very different from whatever it happens to be. Had I been born in India, I would probably have been a Hindu; in Sri Lanka, probably a Buddhist. Not so for our science: engineers the world over use the same mathematics and physics.

Such reflections suggest to some that there is no truth of the matter in religion, so that impartial evidence and argument do not apply. One way they reach this skeptical conclusion is by a kind of Argument from Disagreement. The long history of interminable disputes over conflicting religious claims is best explained by there being no culture-independent reality for them to be about. Instead, people's ideas about God grow out of their diverse temperaments, languages and histories. Furthermore, or so we may be told, this Argument from Disagreement can be backed by a Queerness argument, and indeed by a Broadened one. For the alleged truth of a religious claim is not derivable from, reducible to, or even nonreductively determined by what all would agree is objectively there. Hence the relation of supposed religious truths to culture-independent reality is quite mysterious. Better by far to regard religious claims as expressing subjective responses to the problems we all face so often in this difficult and sometimes terrifying world.

Theists might respond roughly as moral realists respond to arguments from disagreement. The amount of past religious disagreement is greatly exaggerated, they may say. Furthermore, in today's world of rapid communication and interaction, diverse religious traditions consciously learn from each other and seem gradually to be converging. Above all, there may be an equally good if not better explanation of the religious differences:

Consider the hypothesis that the great religions are all, at their experiential roots, in contact with the same ultimate divine reality, but that their differing experiences of that reality, interacting over the centuries with the differing thought forms of differing cultures, have led to increasing differentiation and contrasting elaboration. (Hick 1983)

The history of differences and disputes would thus be explained by reference to different perceptions or awarenesses of the same transcendent reality.

As for Queerness arguments, theists may say, it remains to be shown, despite some prejudice to the contrary, that religious truth is not determined by what is objectively there. If there is an ultimate divine reality, it too is objectively there, in the sense of having an existence independent of our culture-bound ideas about it. Surely such a reality would determine the truth of religious claims. Moreover, we must not neglect the possibility that the truth of at least some religious claims can be derived from ordinary objective features of the world. Some of the classical arguments for the existence of God attempt to do so, as we'll soon see, and they have their defenders. Nor should we neglect the possibility that even if religious truths cannot be derived from objective features of existence, nevertheless religious truth is nonreductively determined by them.

Skeptics might concede the possibility that eventually some such strategy will be found that works. But until then, we have no good reason to believe either that some religious claims actually can be derived from or determined true by ordinary objective features of the world, or that there actually exists an ultimate divine reality that determines religious truth. Indeed, skeptics claim that we have good reason to doubt there is any such reality. For each religion views what it regards as the Holy as demanding an absolute response of faith, worship and deed, to the exclusion of all that is incompatible with such response. "Within Christianity, for example, this absoluteness and exclusiveness of response has been strongly developed in the doctrine that Christ was uniquely divine, the only Son of God, of one substance with the Father, the only mediator between God and man." This means that believers must regard their own distinctive claims as true and those of incompatible faiths as false. The different religions cannot all be true, and any evidence for the distinctive truth of one is automatically evidence for the falsity of all the others. Since the evidence includes the religious experience and testimony of the believers within each religion, it follows that for any given religion there is always more such experiential and testimonial evidence for its falsity than for its truth.

Generalizing, skeptics go on to point out that any evidence or argument against other religions will automatically be evidence or argument against your own, unless you can point to some relevant difference in virtue of which what counts against those others does not count against yours. The burden of proof therefore falls heavily on believers for giving some reason to suppose that there actually exists an ultimate divine reality answering to their distinctive idea of such a reality. It will not do to spell out the alleged relevant difference between your religious beliefs and those others by appealing to the authority of scripture, to revelation, to faith, to your own experience or that of co-believers, and so on. For these are exactly the same kinds of things alien believers will point to in defense of their beliefs.

In view of all this, we may be forced to conclude that the greatest challenge to theism does not come from atheism, "secular humanism," or reductive scientific philosophies, as is often supposed. The greatest danger may lie in the apparently irreducible plurality of conflicting theisms and the skeptical or agnostic questioning the conflict gives rise to. The reason so many believers do not realize this, says the skeptic, is that they are ignorant of, because they chauvinistically insulate themselves from, the great religions and cultures of the world other than their own.