It was a surprise to me to be awarded the Templeton Prize, joining an eclectic roll-call of scientists, philosophers, theologians and public figures among the previous winners. I feel I tick only one of the relevant boxes: like other scientists who have won it in recent years, I focus on "big questions" (in my case, cosmology) and have made efforts to communicate the essence of my work to a wide public.

I don't do this well, but that skilled expositors such as the physicists Brian Cox and Jim al-Khalili attract such large television audiences indicates the broad fascination with questions about our origins, life in space, our long-range destiny and the laws of nature.

Most practising scientists focus on "bite-sized" problems that are timely and tractable. The occupational risk is then to lose sight of the big picture. The words of A N Whitehead are as true today as ever: "Philosophy begins in wonder. And, at the end, when philosophic thought has done its best, the wonder remains."

Darwinist discontents

It is astonishing that human brains, which evolved to cope with the everyday world, have been able to grasp the counterintuitive mysteries of the cosmos and the quantum. But there seems no reason why they should be matched to every intellectual quest - we could easily be as unaware of crucial aspects of reality as a monkey is of the theory of relativity.

This seems to have been Charles Darwin's attitude to religion, at least at some stage in his life. In a letter to the Swiss-American biologist Louis Agassiz, he said: "The whole subject is too profound for the human intellect. A dog might as well speculate on the mind of Newton. Let each man hope and believe as he can."

This is a glaringly different stance from that adopted by some of Darwinism's high-profile proponents today. We should all oppose - as Darwin did - views manifestly in conflict with the evidence, such as creationism. (Last year's Templeton winner, Francisco Ayala, has been in the forefront of that campaign in the US.) But we shouldn't set up this debate as "religion v science"; instead, we should strive for peaceful coexistence with at least the less dogmatic strands of mainstream religions, which number many excellent scientists among their adherents.

This, at least, is my view - a pallid and boring one, both for those who wish to promote constructive engagement between science and religion, and for those who prefer antagonistic debate. I am, I suppose, an "accommodationist" - a disparaging epithet used by anti-religion campaigners to describe those who don't share their fervour. Richard Dawkins described me as a "compliant quisling".

But I am a sceptic. If we learn anything from the pursuit of science, it is that even something as basic as an atom is quite hard to understand. We should be unsurprised that many phenomena remain unexplained, and dubious of any claim to have achieved more than a very incomplete and metaphorical insight into any profound aspect of our existence - and, especially, we should be sceptical of dogma. This is certainly why I have no religious belief.

Despite this, I continue to be nourished by the music and liturgy of the Church in which I was brought up. Just as there are many Jews who keep the Friday ritual in their home despite describing themselves as atheists, I am a "tribal Christian", happy to attend church services.

Campaigning against religion can be socially counterproductive. If teachers take the uncompromising line that God and Darwinism are irreconcilable, many young people raised in a faith-based culture will stick with their religion and be lost to science. Moreover, we need all the allies we can muster against fundamentalism - a palpable, perhaps growing concern.

Mainstream religions - such as the Anglican Church - should be welcomed as being on our side in any such confrontation. (Indeed, one reason I would like to see them stronger is that the archbishops who lead the Church of England, Rowan Williams and John Sentamu, two remarkable but utterly different personalities, both elevate the tone of our public life.)

Pale blue dot

And not even the most secular among us can fail to be uplifted by Christianity's architectural legacy - the great cathedrals. These immense and glorious buildings were erected in an era of constricted horizons, both in time and in space. Even the most educated knew of essentially nothing beyond Europe; they thought the world was a few thousand years old, and that it might not last another thousand.

Unlike the cathedral-builders, we know a great deal about our world - and, indeed, about what lies beyond. Technologies that our ancestors couldn't have conceived of enrich our lives and our understanding. Many phenomena still make us fearful, but the advance of science spares us from irrational dread.

Some might think that intellectual immersion in vast expanses of space and time would render cosmologists serene and uncaring about what happens next year, next week, or tomorrow. For me, however, the opposite is the case. We know we are stewards of a precious "pale blue dot", a planet with a future measured in billions of years, whose fate depends on humanity's collective actions this century.

In today's fast-changing world, we can't aspire to leave a monument lasting 1,000 years, but it would be shameful if our focus remained short term and parochial, and we thereby denied future generations a fair inheritance. Wise choices will require the effective efforts of natural scientists, environmentalists, social scientists and humanists. All must be guided by the knowledge that 21st-century science can offer - but inspired by an idealism, vision and commitment that science alone can't provide.

Martin Rees is Astronomer Royal and Master of Trinity College, Cambridge