The acceptance of deep time — of the fact that the universe has existed for billions of years and that it will continue to exist for billions of years — could, if inwardly digested, have a radical effect on human religious beliefs. In the first two chapters of this book, Schellenberg presents the scientific arguments for this view, and argues that the far-future beliefs of whatever succeeds the human species are liable to reduce our own early and primitive beliefs to virtual irrelevance. This is true in science, and we should expect it to be true of religion, too.
You could see this as the cosmic and temporal analogue to recognizing that human religious beliefs already vary widely across different communities. For many people, realizing that their own beliefs are at least partly contingent upon chance and circumstance introduces an element of doubt. The thrust of Schellenberg’s argument seems to be that contemplating what our beliefs may look like to our far-future descendents is cause for even greater skepticism.
Ward provides some good reasons for thinking that we needn’t lapse into wholesale religious skepticism, though. If there is an ultimate reality that human beings can come into contact with, it seems plausible that our experiences of it to date would not be wholly misleading.
I suspect that anyone who postulates that there is a supremely valuable source of universal and ultimate good will expect to find some specific instances of human contact with, and transformation by, this good. A search for revelation will begin, and you might expect to find that while such instances do not disclose all the truths there are to be known about the ultimate, nevertheless they provide accurate information which is not seriously misleading about the nature and goals of human existence.
But he also says that Schellenberg makes a strong case that “religious believers should be much less dogmatic, especially about very detailed and obscure and controversial beliefs” and that they should be more open to developing their beliefs in light of new insights.
I do think that Christians in particular are prone to thinking that most of the important development of our religious beliefs has already happened. We look back to the writing and formation of the Biblical canon, the great councils of the early church, and maybe the Middle Ages or the Reformation (depending on our church affiliation) as codifying, more or less for good, the right way of understanding who God is. This is probably inevitable to some extent because Christianity is based on a historical revelation. But another important motif of Christian faith–though one not emphasized as consistently–is the messianic, future-oriented dimension. Christianity teaches that the Kingdom has not come in its fullness and we still see “in a glass darkly.” This might lend support to the idea that our current beliefs about ultimate reality will undergo indefinite revision. But this has to be kept in balance with the conviction, which most Christians would share, that the life, death, and resurrection of Jesus provide a reliable indication of what God is like.