Jesse Moss’s tough, absorbing documentary could almost be a modern-day Grapes of Wrath, all about the US oil industry’s fracking boom in North Dakota. A local pastor, Jay Reinke, has set up a programme to let homeless transient workers sleep in his church and even his house. These men, from all over the US, have been lured to the area by the mostly illusory promise of plentiful jobs and easy money in the oil business. Driven by constant stories in the local press about criminals and sex offenders among these men, Reinke is under intense pressure to abandon the scheme. What would Jesus do?

The movie finally punches you – maybe even sucker-punches you – with Reinke’s own backstory: he has been passionately committed to his radical Christian ministry despite, or perhaps because of, a secret emotional burden. Moss has filmed some extraordinarily intimate scenes that look nothing other than authentic, although audiences are entitled to ask at what stage Moss knew what was happening in Reinke’s life, the revelation of which facilitates that big finish. Well, no matter. From a religious point of view, it is a story about one man’s state of grace; from a secular perspective, it is about politics and society. It is a very powerful, contemporary study.