Last weekend a conference took place in Lynchburg, Tennessee. It's the home of Liberty University, whose president is Jerry Falwell Jnr, one of President Trump's most ardent evangelical supporters. However this conference was run by 'Red Letter Christians' who are at odds with Falwell and all his works. The feeling is mutual: an offer to come and pray with him was met by threats of legal action.

'Red letter Christians'? It sounds like some sort of gift voucher scheme.

Not really. It's a progressive movement started by Tony Campolo and Shane Claiborne, light on doctrine and heavy on social justice.

Ah: heretics.

The answer to that is somewhere between, 'Don't be ridiculous' and 'It depends what you mean by heretic.' By 'light on doctrine' I mean that they aren't really interested in stuff large sections of the US evangelical world major on, like predestination and particular theories of the atonement. They are, in general, theologically orthodox.

In general?

Tony Campolo has affirmed his support for gay marriage. But the problem many evangelicals have with Red Letter Christians (RLC) is that they are more interested in changing the world than in the more tribal aspects of church life. On its website, RLC talks about its 'values', including: 'All people are made in the likeness and image of God', 'Doing Jesus' work leads to personal growth and greater understanding', 'Freedom comes through serving others—not power, politics or materialism' and 'We respect and fight for the well-being of all people as children of God – especially those with whom we differ.'

And is there a statement of faith, like most Christian organisations have?

Nah. The ultra-conservative 9Marks website has a review of Shane Claiborne's book The Irresistible Revolution in its False Gospels section. It says its theology is 'an unbiblical and incoherent synthesis which might be described as popularized Christian anarchism for young, disaffected, middle-class Americans' (though it does praise his 'great moral clarity and bravery').

So they tend to do stuff rather than think about stuff, then?

To a degree, yes. Shane Claiborne held a Jubilee party at the New York Stock exchange in which they scattered money from a legal windfall around. But they campaign on things like race, immigration, justice, peace and corporate responsibility, all issues that put them right in tune with socially conscious young America. They don't tend to major on the traditional disciplines of academic theology, which is what irritates conservative evangelicals; it's more experiential and practical than that.

Not, perhaps, natural Trump supporters?

No, which helps explain the visceral aversion to them from some quarters.

What about the Red Letter thing?

In some Bibles the words of Jesus in the Gospels are in red. The practice is regarded with deep suspicion by conservatives who argue that the whole Bible is equally inspired. This suspicion is borne out by the RLCs, who major on Jesus and his words and try to steer clear of doctrinal controversies.

Sounds smart but risky.

It's a smart strategy because it helps get things done and you don't have to argue about predestination, but it allows people to paint you as heretics or not-really-theologians.

So who's likely to see out the century – Red Letter Christians or 9Marks?

Discuss.

Follow Mark Woods on Twitter: @RevMarkWoods