I will always remember the first time I looked at Jan van Eyck’s Arnolfini Portrait, painted in 1434. At first glance, I dismissed it as rather formalised, the two principal figures stiff and lifeless and a painting with no vitality or special meaning. I was soon put right, and was stunned.

It is in fact an extraordinary painting with exquisite detail that imparts a whole new understanding of what the artist was conveying. The mirror on the wall behind the figures, for example, contains in minute detail a reflection of the whole scene, including the two witnesses to the event (one of them the artist himself), with all the precision of a modern digital photograph. Yet I missed this completely the first time I saw it.

I have now concluded that the same applies to the way we look at the world around us, and the amazing story that science has uncovered about our universe. When I began to really examine this – the cosmology, physics, biochemistry, environmentalism, socio-biology and spirituality that have brought us here and made us what we are – I realised that there were significant nodal points which were easy to pass over, but which, once identified and understood, shed new light over the whole landscape.

We live today in the West in a secular age where the old certainties underpinned by religious dogma and an unquestioning morality have largely faded, to be replaced by consumer materialism in thrall to wealth and celebrity. So I asked myself what do I really believe in? Are our lives simply a temporary rite of passage that soon vanishes with little or no meaning or is there some greater order of things giving meaning to our species? And if so, what is the scientific evidence for this?

I am not someone who has had an overpowering experience leading to an unshakeable inner certainty. Raised as a Christian, my mother wanted me to become a priest but I opted instead for social work, as a probation officer, before becoming focused on achieving social change through the political process; a shift which took me into Parliament for the next 40 years.

Whilst this choice offered important opportunities to fight for the values I believed in, it gave no respite from puzzling the deeper meaning of human life and what it is ultimately for – if indeed it is ‘for’ anything.

I have always had a lifelong passion for science and so have read extensively, particularly about cosmology and, given that reality has to be one single indivisible unity, I pondered how it all fitted together. It has always seemed strange to me that some people assert that modern science has ‘disproved’ religion, since this is clearly wrong – science and religion simply reflect two different paradigms of experience, so neither can invalidate the other.

I decided to write my book from the standpoint of the spiritual agnostic – a place that reflects where I think most people in modern society are: namely, uncertain, sceptical and unwilling to make any intellectual or emotional commitment without being shown ‘the evidence.’

So, what is the relevant evidence that is available to us?

My book surveys each of the critical dimensions – the origin some 13 billion years ago and evolution of the universe, the formation of the galaxies and our solar system, the possible origins of life on Earth some 4 billion years ago and the subsequent proliferation of exotic life forms leading through a chain of the most unlikely improbabilities to the human species.

I asked myself what we can learn when we look at the sometimes hidden detail – like searching for the minutiae of the van Eyck painting – that illuminates the whole, bringing it to life? And I found there are indeed patterns drawing the threads together in coherent if often unexpected ways.

The story is an extraordinary one. Less than a century ago Hubble, the American astronomer, discovered that the galaxies were not static (as Newtonian physics had believed), but flying away from each other at incredible speeds. Winding back this process – using the Hubble constant – suggests the universe began in a cataclysmic explosion some 13.7 billion years ago (the so-called Big Bang). But the one scientific fact that sticks out is that the universe has been constructed with mind-boggling precision.

In order to produce this stable universe, the balance between the original outward explosive force at Big Bang and the gravitational forces pulling the galaxies back is precise within an accuracy of one part in one followed by 60 noughts! Mathematician Roger Penrose has calculated the likelihood of the universe being random at one chance in one followed by 123 noughts – a degree of unlikelihood verging on infinity. But whilst the scientific data strongly suggests the universe is designed, to make a simplistic ‘leap’ from this to a designer God is still not warranted, at least not on the scientific evidence we now have.

The paradox of design, however, is that it is interwoven with constant episodes through which the universe is recycled with unimaginable violence and destructiveness, as in supernova explosions, gamma ray bursts, and collisions of galaxies. The Earth itself was pummelled by massive bombardments for some 200 million years after it was formed 4.5 billion years ago, and there have been at least six, perhaps even ten, mass extinctions in Earth’s history.

The moon was formed when an asteroid the size of Mars crashed into the Earth at 25,000 miles an hour, with a force equal to some 50,000 trillion Hiroshima atomic bombs. But, paradoxically again, this gigantic cataclysm was the bearer of critical conditions for life on Earth: the axial tilt, the modulated climate, the slowed rotation (so there are no winds at 200 miles an hour), and a very powerful magnetic field warding off lethal cosmic rays.

The evolution of life forms on Earth is equally puzzling. The conventional picture of the smooth upward linear enhancement from primeval mammal to modern man could hardly be more wrong. Life (however it began) would never have proceeded at all without a whole series of unpredictable environmental conditions, including photosynthesis, an enormous rise in the incidence of oxygen, and the advance from prokaryotic to eukaryotic cells.

Proto-mammals, the ancestors of humans, were all but wiped out in the Permian mega-catastrophe 251 million years ago. They just survived, but then lost out to their semi-reptilian competitors, which were then displaced by the dinosaurs, which dominated the world for 165 million years before they too were wiped out by the asteroid strike off the Gulf of Mexico 65 million years ago.

This might suggest a universe that is purposeless and devoid of any overall meaning. However, look closely again and a rather different picture emerges. Consistent with this free play of natural forces of unbelievable power and violence at the macro level, there is much subtler evidence of detectable and positive patterns of activity at the micro level. There is growing evidence of a natural process whereby at certain thresholds of complexity matter and energy are transposed spontaneously into new higher organisational states not derivable from lower-level laws. This is very different from neo-Darwinian theory, which does not predict increased complexity, but only gene reshuffling through blind, pitiless chance.

Nor is this just a function of biological systems. New evidence is being discovered of this transition to a qualitatively different order of organisation in cosmological systems as well. It is a remarkable new finding that spiral galaxies display autocatalytic cycles of energy and matter just like those that underlie the ecology of the biosphere. It’s as though we are gradually becoming aware of some cosmic blueprint.

We need to be careful, however, about what all this means. The evidence in favour of the universe being designed is very strong, but that does not automatically equate with a personal God. For that, a different set of criteria is necessary.

Religious experience is validated, not by scientific verification, but from quite separate sources: the awesome sense of numinous power found almost universally in human societies, the revelations proclaimed by the founders and prophets of the world’s great religions, the ineffable witness of the mystics, and the authenticity of overpowering personal experience which transforms lives. For all that, the narrative of the universe and the link with religious experience often seem contradictory – a mystery we can still only dimly penetrate.

For three centuries science has progressively narrowed the significance of humans against the almost infinite backdrop of the universe, and maybe an almost endless series of universes. It seems odd to attach much importance to a species – ours – that lives on a planet within the solar system of one mainstream star in a galaxy that contains some 200 billion similar stars within a universe that contains perhaps 100 billion other galaxies. It seems odd, too, to design a world for humans in a way that leaves the species off the stage until the last 0.0006% of the time of the near-14-billion-year (so far) performance.

Yet the evidence is pointing now to an ultimate reality, certainly not of the human race as the summit of evolution, but of an overarching cosmic plan of which we may well be a key part.

Michael Meacher is a Labour MP and author of Destination of the Species: The Riddle of Human Existence. www.michaelmeacher.info