The Christians (Traverse Theatre, Edinburgh)

Religion is big business in America. "This church," says the Southern pastor, preaching out to us, his congregation, "is a massive corporation." Under his tenure, it has grown exponentially. It's new premises seats thousands. It has a coffee shop and a bookstall. Today, the pastor adds, it has paid off its mortgage.

Lucas Hnath's begs a big question about belief — which is the more important: integrity or consensus? Ought one to stick to your convictions, regardless of how many people share them, or the size of your congregation matter more than the small print? That feels particularly pertinent this summer, with the Labour party split between its core values and electability. Do we want out representative leaders to lead or to represent?

William Gaminara's Pastor opts to mark the end of debt by announcing an epiphany, namely, that hell exists only as a metaphor. It's not a position shared by his conservative Associate (Stefan Adegbola) nor, when it's put to a vote, by many of his flock, who break away to form a new church. One chorister (Lucy Ellinson) wants to know why he waited until donations had cleared the debt before making the sermon. Even his wife (Jaye Griffiths) voted against him and her husband takes his professional frustrations out on her at home: a private argument played, very deliberately, as a public debate.

It's a sober play, unleavened with humour and often dry as a communion wafer, but it is an important one. Hnath's writing about Christianity, for sure, and the specific tussle between liberalism and literalism feels as contemporary as ever, but beneath, it's a metaphor for democracy in process. (Their faith is crucial: it allows us to accept that both sides have decent intentions, and puts the debate, not the debaters, centre-stage.)

It's telling that Oliver Townsend's design places the Pastors on a raised platform, speaking into microphones, and Christopher Haydon's production makes clear that this is also a play about privilege. Hnath pushes for multiplicity: the Pastor's wife hopes to offer a counter position in-house at her own Bible Studies group. Can a corporation contain contradictions? Can society?

The Christians runs at the Traverse until 30 August, after which, it will transfer to the Gate Theatre, London, 8 September to 3 October.