My faith has always been an important part of my politics. While in office, it was best, in my view, not to shout that too loudly from the rooftops, lest it be thought that I was trying to claim some kind of moral superiority for myself or my party. On the rare occasions when I did talk about religion, it tended to be misrepresented to suit the political purposes of others. That was the reason why “we did not do God”.

Out of office, seeking to make a contribution to important public and policy debates in a different way, I feel no such restraints. Indeed, as the years of my premiership passed, one fact struck me with increasing force: that failure to understand the power of religion meant failure to understand the modern world. In western Europe this may sound counter-intuitive. Almost everywhere else, it stares you in the face.

Briefly, consider the statistics: more than two billion Christians worldwide, almost 1.5 billion Muslims, more than 900 million Hindus, 400 million Buddhists, 24 million Sikhs, 13 million Jews. And these figures exclude adherents of other faiths. In most places these numbers are growing. In Africa, for example, there were ten million Christians in 1900; by 2000, there were 360 million, the largest quantitative change ever. And people of different faiths are being brought closer and closer together. Walk down many UK high streets and you see a microcosm of the world’s faiths in a few yards.

In this globalised world, we are more than ever interconnected, but we are also more uncertain. What were firm boundaries of race, culture and identity are becoming fluid. In such a world the involvement of religion becomes ever more crucial. It can either play a positive role, helping to deepen understanding and working for the common good, or it can be exploited to become destructive, emphasising difference and reinforcing distrust of the “other”.

Religious faith and how it develops could be of the same significance to the 21st century as political ideology was to the 20th. It could help guide and sustain the era of globalisation, lending it values, and, in bringing faiths and cultures to a greater understanding of each other, could foster peaceful coexistence. Or it could be a reactionary force, pulling people apart just as globalisation pushes people together. Whichever route develops, it does mean that all leaders, whether of religious faith themselves or not, have to “do God”.

I set up the Tony Blair Faith Foundation with the aim of promoting greater respect and understanding between the major religions, to make the case for religion as a force for good, and to show this in action by encouraging interfaith initiatives to tackle global poverty and conflict. We hope to show the relevance of faith to the challenges of the 21st century and its ability to bring people together, not force them further apart.

We are focusing on five main projects initially, working with partners in the six main faiths.

First, we have developed Faith Acts Together, a programme already involving supporters in more than 30 countries on six continents. We are working across religious divides towards a common goal – ending the scandal of deaths from malaria, and thus contributing to the Millennium Development Goals. We shall work initially in selected countries in Africa, bringing different faith communities together to distribute bed nets and offer training in their use, the most effective and the cheapest way to eliminate the preventable death toll from malaria. And, initially in the UK, US and Canada, we are appointing 30 Faith Act fellows, young leaders who will build grass-roots campaigns and coalitions across all the main faiths to support the work in Africa on the ground.

Second, we have established Face to Faith, an interfaith schools programme to counter intolerance and extremism. This will link classrooms around the world through structured and facilitated video conferences. Children of one faith and culture will have the chance to interact with children of another, getting a real sense of each other’s lived experience. The syllabus will focus on leading contemporary topics, such as the environment, exploring what the great faith traditions have to contribute on the issues. The programme is being piloted now in five countries on three continents.

Third, we are developing a deeper intellectual understanding of the dynamics of faith and globalisation. My foundation and Yale University have developed a course on this, which I co-taught last term. Our aim is to build a global conversation between a dozen world-class universities on these issues. We are now discussing with three others how they will take up the course, with more to follow. Each university will bring its own intellectual traditions and regional perspective, but all will explore the relations between religion and economics, politics and society, and how the great faiths might do more to humanise a globalised world.

As part of this we are also exploring the issue of values and the financial system in the light of the financial crisis, examining how our financial systems might be reconnected with some basic values from which they have become largely detached. We have contributed to the global debate, at President Sarkozy’s Paris conference and at the World Economic Forum; we are now exploring ways of translating the debate into concrete action.

Finally, we are working with the Coexist Foundation and Cambridge University to develop the concept of Abraham House. This will be a world-class place of encounter for the three Abrahamic faiths in London, but also open to all of any faith or none. It will provide a national and international focus for a movement of creative thinking and exploration, leading to new action and deeper understanding.

The 21st century will be poorer in spirit and ambition, less focused on social justice, less sensitive to conscience and the common good, without a full and proper recognition of the role that the great faiths can and do play. I hope my foundation, in its own way, can work with others in those faiths to help harness their full power to transform our world for the better.