Cities are "sexier and more beautiful than Eden", according to Sara Miles, who founded a hugely successful feeding scheme for the poor in her city, San Francisco. Miles, whose own conversion followed wandering into a San Francisco city church and taking communion, founded The Food Pantry in 2000 as an extension of that experience.

"The food pantry was explicitly modelled on what I had experienced in the Eucharist," she says, "so it's not a social service programme. We don't ask people for ID or to prove anything, because Jesus welcomes everyone." The Food Pantry feeds 400 families with food provided by local food banks and run mostly by volunteers, mostly from the city's Mission District, an area known for its cultural, racial and economic diversity.

Miles talks about the group of volunteers that has formed around The Food Pantry based at St Gregory of Nyssa, the church where she dramatically met God when she was 46 years old, as being a 'Eucharistic Community'. "They are almost all people who came to get food and still get food, but now help out," she says. "They see St Gregory's as their place, and they run it."

Having had a profound supernatural experience of God during her first, almost accidental Communion (detailed in her book, Take This Bread), Miles sees providing food to the poor as more than just "doing something 'social servicey'," and her sense of those involved with The Food Pantry being a "covenanted community" is expressed in the centrality of the altar at St Gregory's. "That altar is the centre of everything," she says. "We have communion on it, we have coffee hour on it. On Fridays we transform it into this gigantic free farmers market."

The situation of St Gregory's and The Food Pantry in the heart of a city have been far from incidental to Miles' own faith. "One of the things is in san Francisco which was also a huge gift to me, is that nobody goes to church who doesn't want to," she says. "Nobody goes to church because their parents do and it's just what you do. It's so not done that if you go to church you actually probably mean it on some level." Miles says that in a secular culture like San Francisco's there is not much room for 'going through the motions' and that going to church is actually "countercultural".

And while Miles' background as an atheistic journalist means that many of her friends initially found her conversion odd, others, she says, knew that she was, at some level, looking for God. "People think it's sort of odd, you know, a little kinky," she says. "But I also think people are frequently hungry. And we're living in a time where it's not as if the secular project is wildly successful. Some people have made me their 'chaplain'."

Against this mixed backdrop of seekers and 'covenanted' volunteer-beneficiaries surrounding The Food Pantry and St Gregory's, it is easier to understand Miles when she says, "Paradise is a garden but Heaven is a city," as she did at Greenbelt festival in August. Talking about her experience of "the Spirit just whipping through the city" one Ash Wednesday (the central story of her latest book, City of God), Miles said that the city "is so apparently impure it proclaims a love vaster than we are used to."

"Living in a city and being part of the flow of that life is to see that God is bigger and that we are not making him in our own image," Miles told a packed venue at Greenbelt. "The blessing, as all cities keep showing us, has been let loose. God has left the building."

Years after her conversion, after founding her Eucharistic community among the misfits and hungry of her city, Miles discovered that Gregory of Nyssa, whose name adorned her church, had written, in a way, of the connection between food and faith. "Gregory says that the way that we are most like God is in our desire: that God desires us and we desire God," she says. "And that desire, that hunger, is what connects us to God. It's beautiful."

Beautiful, perhaps, as the opportunities God presents us in a city.