Canadian playwright Drew Pautz created ripples at the Soho Theatre with his first play, Someone Else’s Shoes. He now makes waves with his second at the National, a cunningly written clash of religious cultures across continents; and the story of a modern marriage.

Love the Sinner starts in the middle of a religious conference in Africa. The delegates have come to an impasse while discussing homosexual bishops and same-sex blessings. Should they move with the times or worry about re-painting the house of Christianity too often, and too easily?

The African/European stand-off is resolved, with a twist, in the second scene hotel room encounter between Jonathan Cullen’s volunteer white layman at the conference and Fiston Barek’s black hotel porter, a member of the Holy Mountain of Fire mission to the world.

Cullen’s sexually conflicted Michael has “eyed” Barek’s Joseph – in a roomful of clergymen, and one woman, closing their eyes for secrecy – and they are caught, post-carnally, with Joseph asking for help and asylum in Britain. In the play’s third scene, Michael is confronted at home by his wife Shelly (Charlotte Randle) over their childlessness. She’s 39, and desperate.

In the second act, two more great scenes show us Michael at work in his small envelope business, going evangelically crazy until interrupted by Shelly – Joseph has turned up at the house – demanding explanations and sex; and a conference “wrap” in Michael’s parish church, where Joseph has been secreted by Michael in the basement.

It’s an unusually good plot for a modern play. Matthew Dunster’s production, beautifully arranged on Anna Fleischle’s adaptable set of wooden blocks and panels, has one of those fine mini-ensembles – Ian Redford as a kindly old bishop, Paul Bentall as a cringing vicar, Nancy Crane as priest and businesswoman, Scott Handy as an ecclesiastical “suit” -- that seem to sprout so regularly at the NT these days.

And they are led by an exemplary trio of performances: the tortured Cullen, who expresses a crisis in the clergy as a personal problem; the demanding and emotionally volatile Randle, stripping for action in the office; and the outstanding debutant Barek as the gay not-so innocent who puts the jizz into Jesus. We have a strong and serious contender for this year’s most promising playwright.