Don Cupitt's philosopy of religion is commonly described as 'non-realism', a term notoriously difficult to explain.
Philosopher's use the term 'realism' for the belief that things of a certain kind exist independently of our experience of them and our thought about them. (Realism about mathematical objects is usually called 'platonism'.) In the case of religion, one form of non-realism says that God is real for those who believe in him, that God is always 'my God', and that God is internal to religion. Our God is 'the God of our Fathers', the God of a whole great tradition.
The old theologians sometimes distinguish between the absolute and relative use of the word 'god'. God absolutely is 'the god of the philosophers', an infinite Spirit, the Creator of all things, who is also the cosmic lawgiver. He lays down the moral law, and applies real sanctions - Heaven and Hell. This God is God with a capital 'G', and is much the same for traditional Jews, Christians and Muslims.
The relative god is 'my god', that which is of supreme importance in my life, my 'ultimate concern', my guiding light. We hear of a glutton 'whose god is his belly', of Iris Murdoch that 'Plato was her god', and of an Australian cricket fan that his god was the great spin bowler Shane Warne. One way of defining a modern religious non-realism would be to say that the believer recognizes that we cannot prove the objective existence of the old God any more, but we can still take the thought of God as 'our god', and live by it as if it were all true. One lives by the idea of god.
Thus, for the non-realist, to believe in the Creator, is to resolve to treat life as a pure gift; to believe in the Resurrection of Christ is to start living 'a risen life', and to believe in the Ascension is to say 'Jesus is Lord' and live by his teaching. Supernatural doctrines are life-guiding pictures.
Non-realism of this kind has long been common among Lutherans. Because it cannot expect any heavenly reward, it lives the good life, the life of love, for its own sake, and not for the sake of any postmortem payoff.
A surprising amount of biblical teaching points in a non-realist direction. The old objective realist God-out-there was above all a lawgiver, but the Bible already contains sharp criticisms of the moral efficacy of any externally-imposed law. Further, in 1 John c.4 there is a classic analysis of 'God is Love' as in effect amounting to 'Love is God'.
In summary, for realists, everything is out-there and readymade. It comes down to us from God and Tradition. For the non-realist, we have had to make all our own language, and all our own knowledge. As the phrase goes, 'It's all yours'. Can we get used to that idea? Cupitt thinks we must, as soon as possible.
To start with, a non-realist pointedly refrains from saying what realists most want to hear, namely that our views in religion,in logic and mathematics, in ethics, and also about the empirical world, can be, and need to be, objectively true.
Realism is often associated with a 'picture' theory of meaning, and a correspondence theory of truth. A witness gives his testimony, and when his words represent the facts as being such-and-such, then if that is indeed how things are, then he's telling the truth.
Further, in ethics, mathematics and logic the chief principles of the subject are often described as being 'timeless truths'.
In religion, monotheistic faiths often claim that their chief tenets are realistically just true. God really does exist, independent of human faith in him, the Bible really is his Word Written, the body that died on the cross really rose and walked on Easter Day, the eucharistic bread and wine really do become the Body and Blood of Christ, and so on. The believer wants to think that in prayer he or she comunes with a real divine person out there. Finally, a particularly strong example of theological realism is the doctrine of Creation, which claims that we live in a complete, finished and ready-made world, specifically designed to be a home for us.
Cupitt points out that the Death of God, the Creator, entails the death of the ready-made Creation, and even also the death of the Soul or core-self.
In philosophy, realism begins with Plato, in whose day theory and abstract conceptual thought had only recently been invented. Philosophers felt they were moving in a world of timeless Forms, contemplating which was a new elite way to knowledge. Plato himself taught that there was a whole really-existing world of Ideas or Forms. But Aristotle objected, saying that the forms were just concepts in our minds - the general ideas which we use to classify things and build our knowledge of the world.
Aristotle's 'conceptualism' was radicalised by Kant. This led to the novel idea that we are the creators. We are given only a chaos of raw sensations, which becomes an ordered world in and through our knowing it. We invent and apply mathematics; we invent the Laws of Nature, and make them work; and we, by the way we describe it, order and interpret the common human world.
Going still further, Nietzsche says 'There are no facts, only interpretations', and, 'The last truth is that there is no truth' - by which he means that in the end truth cannot be more than an ever-shifting human consensus that invokes a 'mobile army' of worn metaphors. There is no readymade Truth-out-there: human interpretation goes all the way down.
That is anti-realism. Nietzsche is at last becoming fully post-platonic, post-metaphysical: he is asking us to live like creative artists, who pour themselves out into their oeuvre, the world they build. There are no 'absolutes' and nothing is just given. In this bleak modern vision of the human condition, can we say with Nietzsche, a great Yes to life? Or will we have to be much more sober and gloomy, like Samuel Beckett?
Don Cupitt's work asks if there can be a viable and cheerful non-realist philosophy of religion.
Following Kant, Cupitt speaks of God as a guiding Ideal, an imaginary focus of religious aspiration. His thinking involves a major shift, from Law to Love, from putting doctrine first to putting ethics first, and from the ecclesiastical period to the 'Kingdom' period in Christianity's scheduled historical development.
These ideas were first announced during the 1980s, but they are still slowly developing. The following list sketches some of Cupitt's chief supporting arguments:
Realism practises religion dutifully for the sake of a heavenly payoff. Non-realism is much more spiritually advanced, because like Buddhism it teaches and demands thoroughgoing selflessness. The self is to be spent not saved.
The problem of evil is fatal to realistic theism, whereas for non-realism it does not arise. The world is our own somewhat-botched work of folk art, and its faults reflect ours.
Realists, like youthful suicide bombers, are too easily induced to waste their only life in the illusory hope of attaining heaven. Non-realists simply accept that we are transient, and live hard.
We already take a non-realistic view of other people's gods. The national gods of Egypt or the Norsemen were cultural projections, embodying cultural values. Accepting critical thinking obliges us to take the same view of our own religious objects. Resort to them if it helps, and if it doesn't, don't.
During the 'Church' period of Christian history (c.AD48-AD1789), human beings were thought not yet ready to live the 'solar' ethic in the Sermon on the Mount. The state used a great deal of brute force to check people's violence to each other. But since the French Revolution the state has become ethical. It looks after us. Today, liberal democracy, the welfare state, the healing professions and our 'humanitarian' moral concern have created a world in which it is easy to see that we can and must live by the ethics of Jesus. Give blood? We do, now. And we can see that the Church is out of date in its attitude to women and gays.