See what I mean? You simply declare that people who disagree with you aren't Christians and shazaam, problem solved.
Incorrect.
There is an historical record which is quite well-documented for over twenty centuries as to what Christians believe.
Up until the late 1800s all professing Christians believed in the physical resurrection of Christ, and those professing Christians who ceased to believe in the Resurrection - like the Unitarians - had the intellectual and moral honesty to declare that they were no longer Christians.
It's not what I personally think that defines Christianity - it is the unbroken witness of the Christian community since the Resurrection.
By your argument, one would not even have to believe that Jesus ever existed or that anything in the NT was valid or useful to be a Christian. Simply making the claim is enough.
That's an intellectually frivolous position.
So your position is that you can be a "Christian" and yet think that Jesus is a liar?
Unitarians aren't really Christians. Unitarian fellowships wellcome atheists, agnostics, Wiccans, - you name it.
No core belief system.