This article was published first on May 25, 2016.

CH Spurgeon was a great believer in hell. In his sermon The Resurrection of the Dead, he goes into considerable detail about it. "You have seen the asbestos lying in the fire red hot, but when you take it out it is unconsumed. So your body will be prepared by God in such a way that it will burn for ever without being consumed; it will lie, not as you consider, in a metaphorical fire, but in actual flame," he says.

Spurgeon imagines the body joining the soul at the day of judgment, whereupon "thou wilt have twin hells, body and soul shall be together, each brimfull of pain, thy soul sweating in its inmost pore drops of blood, and thy body from head to foot suffused with agony; conscience, judgment, memory, all tortured, but more – thy head tormented with racking pains, thine eyes starting from their sockets with sights of blood and woe..." and all this for ever and ever.

It was to save people from such a fate that he preached conversion with such passion. "If sinners be damned, at least let them leap to Hell over our dead bodies," he said on another occasion. "And if they perish, let them perish with our arms wrapped about their knees, imploring them to stay."

Nowadays, it's hard to imagine anyone preaching hell with such conviction. As a doctrine, many evangelicals find it awkward or embarrassing. The idea that someone – in fact, the vast majority of human beings since the beginning of time – would suffer Eternal Conscious Torment (ECT) for the crime of not believing in a God of whom they might never even have heard doesn't ring true.

Nevertheless, the idea that nonbelievers will suffer an eternity in hell is the default evangelical position. But increasingly, it's being challenged from within the evangelical constituency itself.

A National Geographic article from May 13 outlines a serious debate on the subject by scholars committed to the authority of the Bible. It cites Edward Fudge, who in 1982 wrote The Fire That Consumes, a book challenging the biblical underpinning for ECT, as the one who kick-started the debate. Fudge argued for annihilationism or "conditional immortality", whereby people who don't believe in Christ cease to exist after death.

According to Prof James Packer, it was two brief arguments from Anglican evangelical leaders John Stott and Philip Edgecumbe Hughes in 1988 that "put the cat among the pigeons". If these impeccably orthodox evangelicals could do without hell, was it really necessary to believe it? Packer himself wasn't convinced by their arguments, but many others have been. Among them is Rob Bell, whose book Love Wins, which suggested God would save everyone in the end, drew from conservative evangelical Bible teacher John Piper the notorious dismissive tweet: "Farewell, Rob Bell."

Can you be an evangelical and an annihilationist, or a universalist? One author, Preston Sprinkle, certainly believes you can. The author with Francis Chan of the book Erasing Hell, which argued that the Bible taught ECT and a literal hell. But Sprinkle says that the biblical arguments in favour of annihilationism, which he prefers to call "terminal punishment", are much stronger than traditionalists have often admitted and that he only "leans toward" ECT. He says that "a terminal punishment view of hell is – for those of us to prioritise the Bible over tradition, who say we're Protestant and reformed – an Evangelical option".

There's even a website, Rethinking Hell, whose rationale is "exploring evangelical conditionalism", with excellent and honest summaries of the debate.

It's fair to say that not everyone would agree. Prof Denny Burk was a contributor to a major book from Zondervan, Four Views on Hell, in which he argued a traditionalist line. A theological hardliner who believes in ECT, he says: "In the entire 2,000-year history of the Christian church, the near consensus view has been the Eternal Conscious Torment (ECT) view. The recent decline of that view in the West may simply be a sign of Christianity's decline in the West."

And, he says, "Western 'Christians' who forsake the traditional doctrine of Hell tend to be drifting in other crucial areas of doctrine as well." The quote marks around 'Christians' are original and significant: these are not real Christians. 

Another contributor was a British author, Robin Parry, author of The Evangelical Universalist. His book is dense and scholarly, referencing the history of the doctrine, the biblical background and the moral arguments against ECT. But what's interesting is that the time he wrote it he felt he had to do so under a pseudonym, choosing the name Gregory MacDonald. He was editorial director of the evangelical publishing house Paternoster and was worried about the impact on his employers if he was outed as a universalist.

He even did a radio interview with his voice disguised and set up a Gregory email address to be able to respond to critics anonymously. Parry eventually admitted his authorship in 2009. He says in the preface to the second edition: "The actual trigger for the self-revelation was receiving the nth email in my Gregory email inbox accusing me of a lack of integrity and seeking to hinder proper academic debate."

Both Parry's experience and Burk's quote marks – not to mention Piper's dismissal of Rob Bell – suggest that the doctrine of ECT is, in evangelical circles, still not really up for discussion in the way that Preston Sprinkle argues it ought to be. Peter Grice on the Rethinking Hell website refers to the "No True Scotsman" argument (no Scotsman would shave; if a Scotsman shaves, he is no true Scotsman). So if an evangelical doesn't believe in ECT, he is no true evangelical.

The trouble is that more and more evangelicals seem to be pushing back. The National Geographic quotes Sprinkle as saying: "My prediction is that, even within conservative evangelical circles, the annihilation view of hell will be the dominant view in 10 or 15 years." And evangelicals who hold to annihilationism or universalism believe they have a strong biblical warrant for doing so. The Bible is not as clear as we have been led to believe. Spurgeon's certainty about hell was misplaced.

So the question for evangelicals today is, how big is the tent? Will a doctrine that even its defenders admit is morally problematic, seeming to cast God as a sadistic monster, remain a defining tenet of evangelicalism, or is there room for debate? James Packer concludes his examination of Stott's position by saying: "When John Stott urges that 'the ultimate annihilation of the wicked should at least be accepted as a legitimate, biblically founded alternative to their eternal conscious torment', he asks too much, for the biblical foundations of this view prove on inspection, as we have seen, to be inadequate. But it would be wrong for differences of opinion on this matter to lead to breaches of fellowship, though it would be a very happy thing for the Christian world if the differences could be resolved."

Breaches of fellowship, though, are very common in the evangelical world, and hell may well prove to be the next pressure point for unity.