Jonathan Edwards was a runner and at one time refused to run on a Sunday, denying himself the opportunity of medals. He later changed his mind about this, after examining biblical texts. But his examination of texts was on the surface, on a literalistic level. He lost his faith and became an agnostic (but assumes atheism) when his television career in religion began. Songs of Praise might have been easy, but in 2007 he put a stop to that, because his faith was examined by a deeper examination of the tradition and texts. The key evidence is an interview given to The Times [behind a paywall].
"Once you start asking yourself questions like, 'How do I really know there is a God?' you are already on the path to unbelief," Edwards says. "During my documentary on St Paul, some experts raised the possibility that his spectacular conversion on the road to Damascus might have been caused by an epileptic fit. It made me realise that I had taken things for granted that were taught to me as a child without subjecting them to any kind of analysis. When you think about it rationally, it does seem incredibly improbable that there is a God."
In other words, something relatively speculative like the earthquake and epileptic fit cause of St. Paul's experience (never mind the simpler subjectivity of such experiences - and a culturally on the cusp person seeking a purpose in life) could shatter belief into the improbability of God.
Not all evangelicals undergo such overnight loss, though I suspect that they are the most likely to do so. The reason is that the hurdle of belief is set so high and is so unsupported that doubt of a significant kind leads to a crashing down of what there was.
Many an evangelical starts on a slippery slide. Some of them do it at theological college, and indeed I have met some at different stages. A Baptist who started at the same time as me said to me that he thought the enemies were outside the Church and now he finds them inside. He was quite tough and self-certain. But I have met others, including some in Sea of Faith, who started out as evangelicals and had become enthusiastic non-realists (and far more enthused than me). Some end up with compromises, retaining a theism whilst most of the doctrinal connections have gone. A URC woman in training was decidely not christocentric but retained an overall theism.
I think there are two kinds of evangelical here. One is the person who must have it all, and one is the person who can settle somewhere else. The Jonathan Edwards person is one for whom the whole lot collapses. He probably hasn't gone into all the details about why there might never have been a bodily resurrection, etc., but rather is just aware of theologians who have come to that conclusion.
But there are more. There is also the person who wants it all, and has to deal with the ever-growing set of questions. This person is likely to be charismatic, whose evangelicalism has been supported by emotional personal experience. The way to tackle doubt is to get back into that personal experience, and relive what used to be the case.
Another supporting mechanism is the Church, by which I mean denomination (I use capital C). Those with doubt can exist in a narrow Church and have the tribe supporting him or her. The Church may well give the emotional support, or revise the old arguments.
But, in the end, the tribe cannot overcome niggling doubts, and there are plenty of sociological studies of people joining cults that show just how feeble is the view that members are brainwashed. All these groups, whatever the force of dogma and generated experience, suffer losses of people after a variety of other arguments come in (some of them start as questioning leadership ethics and patterns of authoritarianism).
Personal experience might pump them up too, but if the canvas is broad the effectiveness of yet another intake of gas is going to lessen.
Church, as it broadens, or a section of the Church, might act as a resistance. One noted pattern of development, for some, is the increasing reliance on 'corporate faith' as a pattern and more ritualistic worship as a support. Unlike the gassy, charismatic stuff, the ritualistic is a theatre of patterns to observe, and this falls in with a 'whole Church view' of inherited culture.
Some of the above can even be non-realist, a postmodern form of premodernity. I suspect that, for an evangelical, this is unattractive. Evangelicals are essentially modernists, people who think they have demonstrable truth, and to move to a kind of mythic existence is not how their brains are wired. They might become militant non-realists, but would do so in a plural or secular form of religious humanism that draws on aspects left over in Christianity; some are forced, meanwhile, to engage with whole liturgies that are otherwise fairly bankrupt in terms of providing information. It must be uncomfortable, and only really possible in Catholic type Churches with written liturgies.
Yet evangelicals also have collective, non-realist forms of theology. The whole idea of an ahistorical reliance on the text, and the text as drama and identifier, and the rejection of objectvity in culture (from Barth to Frei and Lindbeck) is also a rejection of personal experience (seen as a form of individualism - and that is liberalism). Some of these folks can do some time-anthropology by getting back to an eschatological Jesus, but their main emphasis remains on the full Pauline text that jumps the Jewish primitive interpretation of end days into a salvation faith (originally too of end days). History might be attempted, but in the end history it is not. It's not that some parts are not unhistorical, but that the emphasis is not on history but on the text and the community and the self as subsumed to both.
If an evangelical finds this material attractive, and a way by which those more complex questions can be contained, then I would think that there must be a clash between the once belief in objective truth and this new, hang-it-in-the-air type approach. It is possible to get into all kinds of little details and the meaning-of-the-story, but the niggle is that the performance is somehow lacking ballast from below.
Ministers of the Christian religion are, however, in a double bind, because they are committed to performance. They cannot discuss their complexities in the open, should they appear to be doubts (as indeed they are at least doubts). Academics can become clever at the use of language which appears to be orthodox but clearly is not - this was under way in the nineteenth century when biblical criticism was becoming more than a speciality in German universities. There is this Frei-Lindbeck conserving postmodernism for Protestants and the Reformed, that simply relies on the expression of ecumenical Protestantism.
To be able to shift theology requires a Church that allows such breadth. The problem with such a Church is that it is often broader than the evangelical wants. The corset is just too loose.
Neverthless, some evangelicals don't get on this particular bus. They see that, as soon as the bus stops, they are off on the cold street. It's like the cartoon character with racing feet off the cliff edge - look down and you fall down.
In the end, if there is going to be history, experience and individualism, there is going to have to be an encounter with the liberal stance. Now the liberal stance is broad, and some liberals also are symbolic (theatrical) in expression and others are plain, but they have the difficulty that liturgically they appear to believe more traditionally than they do. There remains a question of honesty. The sermon is also to preach the gospel, not have an open set of expressed ideas, and in the Eucharist service is followed by the creed (just in case the sermon should sway off line).
I think there is a line from an evangelical to a liberal. It doesn't have to be like Jonathan Edwards. But Church has boundaries, and a too-loose corset for an evangelical in transition might well become too tight for a liberal.
Promises are promises, after all. I'm a soft non-realist regarding transcendence, and I understand the role of myth in religion. But history, experience and the individual is important. If I give a sermon, it will be what I actually think (even if sensitive to the ears of others), and if I hear one I want it to be authentic to the person speaking. I want the service to be around the area I believe, with people who are at least prepared to discuss and debate openly. Compromises are still made, but we know what they are and it should not impede open thought. There is a place for symbolism, too, but not as a rope to climb to become something you are not. I like symbolism, but I want it to be expressive and plural too. In the end, religion must be about honesty. One hears Jonathan Edwards in current times, reflecting on his religious past, and he is honest, but liberal religion also ought to be honest. He was honest, when religious too, but I'm only suggesting that a collapse is not the only option.
Incidentally I was never evangelical and was always agnostic, and I'm still in the same region, but on the other side of the religion-non-religion line. I don't have and probably cannot have an evangelical mindset, and also I failed to pump up a given collective symbolism despite attempts to see it as an orthopraxy rather than an orthodoxy. So I am where I am, but there are a small number of native liberals compared with fallen evangelicals and those liberals who dress up.