In a recent discussion with a group of de-converts from Christianity the following objection was raised:
Actually, my article *argues* that there is no objective definition of Christianity; it does not assume it. That was pretty much the point: there is no supernatural referent to “Christian” (or “God” or “salvation” or any of it), so the only definition(s) possible have to do with human social designations. Many groups of course *claim* to have objective definitions, but since I believe (a) they are all wrong, and (b) all lack the authority to settle the question for everyone, I can either scrap the word “Christian” altogether, or understand it to refer only to those who profess to be followers of Jesus. Thus, the boundaries of the term “Christian” are very fuzzy: it doesn’t refer to anything divine, and there is no universally accepted coding system, as it were. So: there is no correct answer.
Anyone is, of course, free to stipulate any definition of “Christian” they wish. You can, if you like, define “Christian” such as to exclude de-conversion. I can’t say that you’re wrong. But there is no reason at all I have to adopt your definition.
Here is my response:
Christianity does have an early and objective definition which has been upheld by all orthodox Christians ever since the establishment of the Church in the book of Acts. In fact, this objective definition is what we use in order to determine whether something is orthodox or not.
This definition is seen clearly in 1 Corinthians 15 where Paul clearly states what many believe to be the earliest Christian creed or codification of Christian beliefs. It contains a number of things but the quick rundown is that Christians believe that Christ is a real person, who died a real death, who then rose from a real grave in a real, physical body and who appeared to real people.
I realize it is very popular to characterize Christian belief in particular (as well as religious belief in general) as merely a product of wish fulfillment or a preference akin to which flavor of ice cream is best (I prefer chocolate). However the fact remains that Christianity is based upon real, historical events which means that Christianity, like Judaism, is potentially falsifiable.
This also means that no one can epistemologically be a “true Christian” unless Christianity is, itself, true. If you have renounced Christianity and now believe it to be false, by definition you also believe you were never a “true believer” because you would have to logically commit yourself to the idea that you were deceived when you held an irrational belief (if, that is, Christianity is indeed false).
Finally, you seem to misunderstand the “no true Scotsman fallacy”. The fallacy is one of lack of objective definition such that the goal-posts are rendered wholly subjective. My contention (as well as Paul’s per 1 Corinthians 15) is that lack of objective definition of what beliefs are definitive of “true Christian beliefs” is simply not true.
We do have an objective standard, rooted in real historical and falsifiable events. Our claims are not entirely subjective, nor are they ad-hoc (as supposed competing explanations of unique Christian claims such as the resurrection are).
So the question of whether you were a “true believer” in the first place must logically center around what you believed in relation to the objective truth claims of Christianity (specifically the resurrection of Jesus) AND what competing, credible, competing theories/arguments/and evidence you have subsequently found that have provided sufficient defeaters to your original beliefs.
In the end, you were either a “true believer” then (of the objective claims of Christianity) or you are a “true believer” now (in atheism/agnosticism). However, die to the law of the excluded middle you cannot claim to have been a “true believer” of both since, at the end of the day, one of them is false and therefore cannot have “true believers” no matter how strenuously it’s adherents may wish it to be true.