Tim Keller explained to people who write about charities and philanthropy the contribution that churches make to “human flourishing”:

Philanthropy: How does a healthy church benefit the community at large beyond its own members? On the flip side, when a neighborhood doesn’t have a flourishing church, what is it missing out on?

Keller: Churches promote cooperation between individuals and the kind of associational life that is necessary for human happiness and social success. Without informal shared trust, things are more litigious and combative. Life is much better when neighbors pull for each other, help each other, collaborate together. But this kind of “social capital” is very difficult to generate through public policy. Governments cannot duplicate the effect of religion as a source of shared values.

Family ties and religious ties are the two biggest sources of social capital. And religion can be fed and bolstered as a source of valuable shared experience. I, as an older white American man, can connect quite sincerely to a single poor African woman in Soweto because we are both evangelical Christians. There’s a powerful bond because we’ve had the same experience of spiritual rebirth. There’s a trust I have that would not exist if I was a non-Christian white man.

Anywhere you’ve got a church, social capital is being created. Especially when the church is attended by people from the surrounding neighborhood. And it’s a big benefit to the community.

Also, church buildings in big cities are a kind of public utility. We bought a parking garage in upper Manhattan and converted it into a church and all the homeowners on the block who were not believers said, “Thank you, you’re improving the whole block.” The city council asked if various local groups could use the building, saying, “We’re starved for space.” Our building became a community center. Organizations can meet there, people can have weddings and other celebrations there. On a Sunday, urban churches create the foot traffic all the restaurant owners and shop owners want. So in all kinds of ways an urban church has huge benefits, as long as it doesn’t have a fortress mentality.

For a fellow with the reputation of presenting the gospel to secular Americans in ways that make it accessible and also clear, Keller comes up short and resorts to language that would actually wind up supporting Roman Catholic parishes, synagogues, and mosques as religious places that increase social capital.