It is the kind of miracle the world's poor need today - the ability to multiply a few pennies into hundreds and thousands of pounds. And it is happening right now among some of the world's most deprived communities in countries such as Ethiopia, thanks to the Christian relief and development agency, Tearfund. It is almost like a modern-day reworking of the Miracle of Loaves and Fishes. What is so significant is that Tearfund is not pouring in cash to these communities. Under the innovative leadership of chief executive officer Matthew Frost, Tearfund has been helping communities use the little they already have to grow it into much, much more.

The process is described eloquently by Alex Evans of Global Dashboard in his blog, What transformation looks like, where he reports on a self-help group in a village near Nazret in Ethiopia. This is not the kind of self-help group we might imagine in the West, one consisting of sharing and consoling. It is more pragmatic than that, and a careful ledger is kept of every member's savings into a common pot each week of five birr, or 15 pence.

It sounds "small birr" and it is. But put together with everyone else's small birr, the numbers add up. Right away, the women can buy discount food in bulk, they can borrow money, set themselves up as small businesses. Soon they are taking out insurance, and starting a livestock business together. 

"In every single case, these are people who were targeted in the initial outreach because they were the very poorest of the poor – the hardest to reach, the most vulnerable, the ones living on a single meal a day if that. Now they have smartphones, sofas, little houses. Some of their kids are in higher education," he writes.

"But here's the thing: they all say that the money's not the point. They're evangelical about the saving, don't get me wrong. But they all say that the thing that's really changed their lives is the relationships with each other."

The Tearfund website cites Meseret Kusma, a member of one of these groups in Ethiopia. "Before, you knew us for our droughts, our poverty. But now the poor are transforming this country, and poverty shall no longer be our name."

After ten years Frost, pictured above in Uganda, last week left Tearfund to spend some time with his family but he will continue to be involved, doing talks about the charity and its work and contributing in other ways. 

Before joining Tearfund in 2005, Frost worked for the Department for Education and for management consultants McKinsey, where he specialised in strategy and organisational leadership. He also served overseas with Medair and set up their aid programme in Afghanistan and served on the board of World Vision.

He is part of a growing tradition of top businessmen leaving the commercial world for the not for profit sector, the most high profile being the present Archbishop of Canterbury, a former oil company executive. Frost, who now worships at Holy Trinity in Claygate, comes out of a similar evangelical tradition as that which nurtured Justin Welby, one rooted as far back as the 18th and 19th centuries in lives such as anti-slavery campaigner William Wilberforce of the evangelical Clapham Sect. This is a tradition that emphasises service as much as faith.

"The reason I joined Tearfund was on the back of a very strong sense of calling," he explained in an exclusive valedictory interview with Christian Today. He had been through a process of reflection at church which led to a conviction that he should be working in leadership in a Christian organisation. In addition his life was changed irrevocably by the birth of identitical twin daughters, both with Down Syndrome. He and his wife Katharine have four children in total. He admits that he found the arrival of the twins, who were born three months premature, "challenging". Their disability was discovered after they were born. "It was a double whammy," he said. They had chronic lung disease, and wherever they went in their double buggy, oxygen canisters had to go as well. "They have taught me so many things. I am a planner. I like to think ahead. They have taught me there is no point. Noone knows what is going to happen to them. You need to focus on today." 

He did the Alpha course at Holy Trinity Brompton in Knightsbridge and has also worshipped at St Mark's Battersea Rise. "I remember thinking, everyone is so happy, smiling and sorted. This point of my life completely up-ended everything. It threw me into God's hands." Through his anger, frustration and disappointment, his eyes were opened to understanding that behind the happy, smiling faces he saw all around him were countless other individual stories of suffering and tragedy. "It shifted my attitude to people I encounter, to look behind the smiling faces, and invest in relationships." He also lowered his expectations for all his children. Rather than imagining spectacular futures, his goal became simply to love them. 

This is at the heart of the transformational gifts he brought to Tearfund and which has made it so effective during his decade there. Also crucial was his understanding that in the context of a Christian charity, both staff and the vast majority of Tearfund's supporters are really, really serious about their faith, as are the front-line partners they work with. "They love Jesus. They are desperate to integrate their faith into every aspect of their lives." How significant this was became clear on his first day on the job, when his first meeting was with the facilities team. He asked them why they were at Tearfund. "Nearly all of them said, 'God called me here.' They all had articulate visions for what Tearfund should be doing." Before the meeting ended, they asked to pray for him. He knew then that this organisation was rather different from the secular world of employment he had come from. This meant he could do things differently. "It goes back to what it means to be a Christian organisation. Does it just mean our values are inspired by Jesus Christ? Most organisations are inspired to a degree by a Judeo-Christian view."

He also had to examine the way in which the Christian faith of the organisation, its supporters and staff affected the sense of purpose of the charity. Tearfund is signatory to the Code of Conduct for the International Red Cross and Red Crescent Movement and NGOs in Disaster Relief. Commitment to impartiality is also underscored in the charity's proselytism policy. "Tearfund's own Christian affiliations do not affect the provision of needs based assistance but rather affirm a calling to respond based on need alone," the charity states. But within, following Jesus, the Christian faith of the organisation, is utterly central to its purpose, and that has been central to Frost's vision over the last ten years. 

Tearfund works in more than 50 countries worldwide although not all can be named for security reasons. Out in the field, Frost discovered the crucial role played in development by the local church. All Tearfund's partners are passionate about empowering local churches because of their ability to transform lives, not just spiritually but materially too. This challenges the assumption often made in the West about what churches do. In developing countries, they can be vital to transforming lives in every way. One of the chief causes of poverty is broken relationships - with families, neighbours, God, creation. Reinstating these relationships is key. 

Here he is talking about what is commonly termed "social capital". And this is how to do sustainable development. The aim is to empower a community to support itself through self-help groups that can be set up, sometimes through the local church, where people can start saving even small amounts and getting organised. Tearfund is thereby supporting a model that can survive with no outside provision, helping people discover dignity, self-worth, purpose. Even atheist columnist Matthew Parris has declared himself a convert to this cause. Writing in The Times after visiting Malawi, he proclaimed Christianity as a force for good in development: "It confounds my ideological beliefs, stubbornly refuses to fit my world view, and has embarrassed my growing belief that there is no God. Now a confirmed atheist, I've become convinced of the enormous contribution that Christian evangelism makes in Africa: sharply distinct from the work of secular NGOs, government projects and international aid efforts. These alone will not do. Education and training alone will not do. In Africa Christianity changes people's hearts. It brings a spiritual transformation. The rebirth is real. The change is good."

Frost has descibed a typical example of how this social capital can be developed in one of his own journal entries:

On the outskirts of Nazareth we visited the 18 members of a self-help group called Brahan, meaning "light" in Amharic. All are women. The transformation of their lives in around six years is stunning. Sunegu is a widow. She had nothing after her husband died, and could not afford to send her four children to school. She began to save 3p every week, all that she could afford. After a few months she had saved £3. She took a loan of £1.50 from the group and used it to buy charcoal which she then sold at a profit. She also bought barley, producing and selling a barley drink, again at a profit. She then returned the loan and a little later took out a second larger loan of close to £5. She invested this in further micro-businesses. And this virtuous cycle continues, always accompanied by the encouragement, support and wisdom of her self-help group peers. Six years later, the fruit is rich indeed. Her oldest child was able to continue schooling, complete university, and is now a lecturer in political science. Her second child has graduated in accounting and has a good job. The youngest two are in secondary school and doing very well.

Through this work, some of the world's most depived people, previously living on a few pennies a week, are now saving incredible amounts - thousands, even millions of dollars, between them. 

He calls this "redeeming development" and would love to see how, for example, this can be translated into other contexts, such as the workplace. He always believed he would do five to ten years at Tearfund, and now aged 50, believes God is calling him now to a broader agenda. For the next year he will "wait on the Lord", and see where he is led. This could be into the Christian environmental movement perhaps, or peace and reconciliation, just two of the areas he is fascinated by. Many areas of life, many organisations, have been damaged or destroyed by broken relationships. Restoring these is his calling, and in this, enabling people to help themselves, he fulfils Jesus's command to be a "good neighbour". This is a different type of target than those we are used to hearing of from chief executives. The work being done by Tearfund is staggering, and as Parris seem to recognise, a model that has massive potential still. It will be fascinating to see where Frost goes next, and whether this faith-based formula can be brought to bear in a failing or struggling organisation in a different field, or simply one looking for a new approach. God surely has more miracles in store for him yet.