I’m willing to bet that any atheist who has spent any time discussing religion online has come across the suggestion that anyone who no longer believes, never truly believed in the first place. An ex-Christian was never a “real” Christian. Commenter al expressed this opinion about myself and Lorena over on Fallen And Flawed a few weeks ago.
… because Jesus Christ has promised that  whoever comes to Him He will never cast out, and that  no one (not even ourselves) is able to pluck us from His hand, therefore:
There can be no such person as a former Christian– only those who think they were once Christians but never really were.
This idea is not dissimilar to the perseverance of the saints – “once saved, always saved” thinking of Calvinism. Leaving aside the theological geekery, the obvious first response to this is that al is committing the “No True Scotsman” fallacy, which can be expressed as:
The pertinent question here being whether the first speaker is trying to make a generalisation about true Scotsmen, or to define what a true Scotsman is – that is, someone who does not have sugar in his porridge. As most people already have a reasonable definition of what a Scotsman is, to redefine it here without saying so explicitly is misleading. If this is what the first speaker had intended it would be better phrased as, “The definition of a true Scotsman is someone who does not have sugar in his porridge” and perhaps some other criteria such as country of birth or parentage.
In al’s case, the assertion comes from the bible, which he interprets as “There can be no such person as a former Christian”. To a biblical literalist it seems, any conclusion – no matter how much of a stretch it is – is better than the bible being wrong. And yet there are plenty of people who changed their mind about Christianity. So, when faced with atheists who claim that they genuinely believed as Christians before changing their minds, apologists are left with few choices.
One is to say that these former believers are lying and only pretending not to believe because they hate God or want to live as they please.
Slightly more charitably, they can claim the ex-Christian was mistaken and didn’t have a genuine relationship with Jesus in the first place. This is what al does.
You both have obviously tried something– church, a belief system, the counsel of others, I don’t know what– but something that represents itself as Christ. But it was not Him, and you have discarded the baby with the bathwater.
Note the subtle shift here. We’re no longer talking about people “being Christians” as most of the world understands it, but the relationship with an invisible, intangible Christ. Christians may complain that it is the same thing, but there’s a difference. The world at large does not define people as belonging to a particular religion on the basis of some invisible supernatural relationship. How could they? Nor do people look inside the heads of professed believers and see all their beliefs – they can only see the way people act and trust what they say they believe. If for example someone says they’re a Muslim, if they attend to Muslim prayers and regularly visit the mosque as other professed Muslims do, then it’s quite reasonable to call them a Muslim. The statistics which show there are around 2 billion Christians in the world are not based on observing whether they each have a genuine relationship with Christ. They’re probably based on what which box they tick on census or identification forms.
However, al says, with an air of authority, “But it was not Him”. I doubt he would claim any special insight into our former religious beliefs. He is inferring that our Christian belief was not a genuine relationship with his god by the simple fact that we no longer believe it. It seems he is making a new definition of what a true Christian is – that is, someone who does not lose their faith or change their mind about Christianity.
However, there are some interesting implications of this viewpoint. If this is not the only way to identify a true Christian, then there is potential for a contradiction. If for example professional ministry or daily prayer were considered proof of genuine Christianity, then there are already many examples of “real” Christians who have become atheists.
On the other hand, if there are no other certain indications of true Christianity that rather throws doubt on everyone. The effect is that there’s no certainty whether anyone, however enthusiastic they might be about Jesus, is a true Christian by al’s definition.
So, if we run with his definition, al can’t be certain that there are any true Christians. I’m sure his relationship seems pretty real to him, but even he could change his mind at a later date.
In one sense I’d agree – I was never in a genuine relationship with Jesus because, as far as I can tell, no such person exists. However, at the time, my belief was entirely genuine, as I would assume al’s still is.