I make a distinction between Christianity on paper and Christianity as rendered by believers and the church.
The distinction I make is between the ideals that are taught, and the students and teachers at different levels of mastery. This is saying sort of the same thing, but with a little clear distinction. The issue is not the teachings. The issue are the schools that don't teach it very well. Because the teachers themselves are hacks, the students rarely rise above that themselves to the ideals of the teachings themselves.
Apologists frequently point to the book, but I look at Christendom to understand the religion.
Masters also point to the book, and are not doing what apologists are doing, which is trying to market religion to consumers with quasi logic arguments. For me personally, the teachings are things that leap out to me that match my own personal experience. They are ways to express them through their metaphoric nature (something I know you don't think exists in them).
Believers frequently say that those people aren't true Christians
There are some who clearly don't even attempt to follow any of the basic principles at all, and simply use the religion as a tool of power over others to manipulate and exploit them. I'd say it's safe to say they aren't sincere at all and are not in it for any spiritual reasons at all.
But for those who do have a sincere intent, then it's really a matter of skill or maturity, from novice to master, just as it is in any path that requires discipline and dedication, such as learning Tai Chi, for instance.
If I went to a park and saw a group of 50 Tai Chi students doing the form, and the vast majority of them were not doing it very well at all, should I conclude that Tai Chi should be dismissed because of them? But isn't that what you are in essence suggesting?
there is no behavioral test for being Christian for me - just an ideological one - the acceptance of Jesus being who others say he was and is.
What you are saying you reject, is what I reject as well. Someone simply "accepting Jesus as their lord and savior" is not at all the test. Jesus himself made that very clear. "By their fruits you shall know them". There has to be changes to the interior of the person, that brings about changes to the exterior. Just saying "yes" and then nothing changes, is nothing at all.
I laugh at how some Christians, particularly legalists will say those fruits are the "fruit of correct beliefs", or the "fruit of obeying the 10 commandments". That's nonsense of course. The sort of fruit that is spiritual fruit are things like love, compassion, forgiveness, non-judgmentalness, mercy, kindness, gentleness, and such. "Obeying the law" is nothing without those. But those who have love in their hearts, will naturally do no harm to others and thus 'fulfill the law' without even trying.
So between the idealized Christian and the one on the street, which is the true Christian and which is the fictitious one?
Love. It's hard for people to understand this, but it is that simple. They need to make it harder, because it supports their ego.
It did me. I walked into a fundamentalist church as an atheist with a girlfriend in 1973 (later a wife), went to the altar, and left it on the road to fundamentalism Christianity for most of the next decade.
This fascinates me. I'd like to hear your story more at some point. In all our discussions I don't think know your background that well, other than the basics.
What I can say to this though is this. Speaking of my own personal experience converting into a fundamentalist church in my earlier 20s. I wasn't religious beforehand either, though I was looking for some spiritual guidance to build upon my Awakening experience I had when I was 18 (I've mentioned this to you in the past, I'm sure).
I grew up in a non-religious home, that was typical modernist home, with modernist values. My father was very much a rationalist, non-religionist. In fact he was quite cynical towards religion, probably much like you in certain regards. So naturally having be raised in that home, as opposed to a pre-modern traditionalist, or magical-mythic thinking household, my mind was fairly logical in how I analyzed things rationally, as opposed to connect the magical dots through prerational magical thinking, and so forth.
Yet for some reason, of the numerous different Christian groups I had more or less "interviewed" to find one explore to find some direction for my spiritual growth, I seized upon a very literalist, black and white thinking, pre-modern, pre-rational, magic-mythic fundamentalist church. I had to suspend my rational mind in the interest to find the spiritual nuggets buried in that magic-mythic heap.
That couldn't be sustained for too long by me however, as committing intellectual suicide for the sake of spiritual growth, was counterproductive to that. You cannot divorce the mind in spirituality, as spirituality encompasses the whole person, body, mind, emotions, psyche, reason, etc.
But it wasn't as simple as just one thing like that either, even though that too was a valid part of it. At that stage of my life-experience, I was more rigid and black and white in my thinking, so this "we have the truth, and everyone else but us is wrong" appealed to that type of thinking I was prone towards at the place in my life. (When I read the OP, that is what I see as well).
My thinking at that time found a home within that. Whereas today, the way my mind sees that everyone has a piece of the truth, and no one has a monopoly of truth itself, would be completely unable to fit into a fundamentalist "we've got the real truth" type of church.
I used to blame the church for making me a black and white thinker, because as I was moving away from that in myself, I naturally didn't want to take ownership of that in myself. But now I can see is that "like finds like", and I did for a time find myself at home within that.
Proof of this can be seen when you see fundamentalist Christians become atheists. Now they take that black and white thinking, and see that only science and reason is the true Light of the World, whereas before it was their belief in their deity, and the truth of the scripture that told them they were on the right side of the truth, and others but themselves were in darkness.
What the religion did do however, which you recognize, is that it reinforced and amplified that black and white thinking. So in that sense, yes it does promote it. But I chose it, like it or not. Today, that would not be a choice. At that time, it was my choice because it appealed to that part of me, which like it or not today, was and is still part of me in my own history.