Is the existence of God a question of fact? Surprisingly, the answer many theologians have given in recent years is, ‘No’. Some of them actually mean that the word ‘God’ refers to nothing at all, so that sentences about God are not fact-stating utterances; but others confine themselves to the more moderate claim that, though there is something to which the word ‘God’ properly refers, this is certainly not an empirical matter of fact, and nor does it imply any empirical facts whatsoever about the world. This more moderate claim is, I think, that of Rudolf Bultmann; and the process of freeing the concept of ‘God’ from all the empirical entailments which have been customarily attributed to it is the programme of demythologising, for the advocacy of which he is well known. In this paper I wish to attack this moderate view, which implies that Christianity could be true, whatever the empirical facts about the nature and destiny of the world; that is, that questions of empirical fact are, not just undecidable, but are actually irrelevant, to the question of God's existence. And I shall refer, in particular, to Bultmann's essay, ‘New Testament and Mythology’ and to the work of the British philosopher, Bishop I. T. Ramsey, who propounds a substantially similar view, though in different philosophical garb.