Is belief in God rational? Can it be proved beyond reasonable doubt? The Bible seems to say yes. 'What can be known about God is plain to people,' writes St Paul in Romans 1.19-20, 'because God has shown it to them. Ever since the creation of the world his eternal power and divine nature, invisible though they are, have been understood and seen through the things he has made. So they are without excuse.'

In this the ancient philosophers agreed, with both Plato and Aristotle holding that the existence of a transcendent God is a matter of solid logical reasoning.

Modern thinkers since the 17^th and 18^th century Enlightenment have challenged this claim, arguing that God's existence can only be known by a leap of faith, if at all. However, Bible-believing Christians have generally stuck by the classical and biblical view that the existence of God is something for which sufficient reasons are supplied by the light of nature. Hence the common use of apologetics in evangelism – reasoned efforts to convince sceptics that belief in God does not require a person to believe, like Lewis Carroll's White Queen, 'six impossible things before breakfast.'

Is the modern anti-rational view beginning to make inroads among believers? That's certainly the impression you would get from UnHerd's Christmas Day piece by Elizabeth Oldfield, director of Theos, self-described as 'the UK's leading Religion and Society think tank'. 

Revisiting her 'book of the decade' - Francis Spufford's 2012 Unapologetic: Why, Despite Everything, Christianity Still Makes Surprising Emotional Sense - Oldfield approvingly quotes Spufford, saying he wants to offer not 'a defence of Christian ideas [but] a defence of Christian emotions – of their intelligibility, of their grown up dignity'.

Oldfield explains that Spufford deems arguments about whether God exists to be 'self-defeating', and so instead seeks to move the debate 'out of the zero-sum dingdong about the Big Bang and biblical archaeology and philosophical proofs – and into the realm of feelings.'

'No, I can't prove it,' Spufford says. 'I don't know if there's a God (and neither do you, and neither does Professor Dawkins ... it isn't the kind of thing you can know. It isn't a knowable item).'

Quite how you can shift a debate from the realm of reason to the 'realm of feelings' and expect to remain coherent (what exactly does 'debate' mean in this context – is the loser the one who feels most sad and bereft, the winner the one who feels most warm and fuzzy?) is not explained.

But Spufford doubles down on this anti-rational move, contending 'it is the feelings that are primary. I assent to the ideas because I have the feelings; I don't have the feelings because I assent to the ideas.'

Oldfield marks this as a 'good and persuasive' move – though what exactly she means by 'persuasive' here I am at a loss to explain (perhaps it makes her feel warm and pleasant or something?) since a moment earlier I'm sure she had shown rational persuasion the door.

Oldfield is disappointingly dismissive of traditional apologetics, claiming that people will still be reading Spufford's book (which, pointedly, has 'no earnest, dusty, churchy tone') once all the Christian responses to new atheist polemics are 'consigned to the recycling bin of history, because it is more powerful, more human, than any of them.'

I don't understand why Oldfield, the director of a Christian think tank, feels the need to be so mean about Christian apologetics. Sure, I can see the value of an approach to apologetics that engages with the emotions and not just the intellect. But is it really necessary to be so down on reason and traditional defences of the faith?

Rational evidence for the existence of God is not 'self-defeating' or part of a 'zero-sum dingdong'. They have been and continue to be advanced by some of the world's leading thinkers and scientists, and have persuaded many people over the years, leading them towards new faith or confirming them in existing belief.

Francis Collins, for example, former director of the Human Genome Project and a Christian, has observed: 'There are 15 constants ... that have precise values. If any one of those constants was off by even one part in a million, or in some cases, by one part in a million million, the universe could not have actually come to the point where we see it. Matter would not have been able to coalesce, there would have been no galaxy, stars, planets or people.' 

Noted Cambridge physicist (and Christian) John Polkinghorne agrees: 'Four fundamental forces of nature operate in our universe. Their intrinsic strengths are determined by the values of four corresponding constants of nature. ... The magnitudes of all these constants are tightly constrained if the universe is to be capable of producing life. If [one of these] were a little smaller, the early universe would have converted all its hydrogen into helium before it had cooled below the temperature at which cosmic nuclear processes ceased. Not only would this have meant no water, so essential to life, but there would also only have been helium-burning stars, which would not have lived long enough to support the development of life on one of their planets. If [it] had been somewhat bigger, supernova explosions would have been inhibited.'

Even atheist scientists are compelled to acknowledge the fine-tuning of the universe. Here's pioneering nuclear physicist Sir Fred Hoyle: 'If this were a purely scientific question and not one that touched on the religious problem, I do not believe that any scientist who examined the evidence would fail to draw the inference that the laws of nuclear physics have been deliberately designed ... A commonsense interpretation of the facts suggests that a superintellect has monkeyed with physics, as well as with chemistry and biology.'

Here's Stephen Hawking: 'If the rate of expansion one second after the big bang had been smaller by even one part in a hundred thousand million million, the universe would have re-collapsed before it ever reached its present size. ... Our universe and its laws appear to have a design that both is tailor-made to support us and, if we are to exist, leaves little room for alteration.' 

Hawking avoided concluding for a Creator by appeal to the highly tentative 'multiverse' theory. However, this idea, which requires the existence of an infinite number of other universes to explain the incredible fine-tuning of this one, has been criticised by many scientists for failing to meet basic scientific criteria of testability. John Polkinghorne has scathingly described it as 'a metaphysical guess of excessive ontological prodigality'.  In other words, it's just made up.

There is also mounting evidence of fine-tuning in evolutionary biology, predetermining the course of the development of life.

God is also required to explain immaterial aspects of the universe, such as consciousness, morality and free will, which, as leading philosopher (and atheist) Thomas Nagel has pointed out, have no plausible explanation within a purely materialistic 'neo-Darwinian' framework.

Nagel opts for 'natural teleology' over theism to explain all this, positing a universe that (for reasons he doesn't explore) 'wants' to become conscious. Perhaps, though, like another famous atheist philosopher, Anthony Flew, he will move towards theism over time. After all, a fine-tuned universe with goals of its own sounds very much like the product of a transcendent Divine Mind, as Plato proposed all those centuries ago.

Ultimately, Francis Spufford is wrong about human beings: we are not entirely controlled by our feelings, and reason is not and ought not to be, as David Hume had it, 'the slave of the passions'. Whatever else we are, we are rational animals, possessed of a reasoning mind, capable of recognising and responding to truth when we see it, including the truth of God.

Seasoned apologist John Lennox spoke at Coventry Cathedral recently on the evidence for a Creator and a colleague of mine went along with an atheist friend of his. Afterwards the friend turned to him and said: 'I now believe in a Creator God'. That is the power of truth.

Dr Will Jones is a Leamington-based writer, a mathematics graduate with a PhD in political philosophy and a diploma in biblical and theological studies. He blogs at www.faith-and-politics.com and is author of Evangelical Social Theology: Past and Present (Grove, 2017). He can be found on Twitter @faithnpolitic