My question is directed to those professing Christians who don't believe in any of the key doctrines as propounded by evangelical Churches ( such as virgin birth, Resurrection, Jesus the only path to salvation). If you believe in the evangelical doctrine of salvation and you believe in evolution but don't believe in either old earth or new earth creationism, then this isn't a question for you.
I come from an evangelical background, and my background taught me to believe in the virgin birth, the resurrection and that Jesus is the only path to salvation. I understand that there are some Christians who don't believe in these things, which I think are the pillars and the cornerstone of Christianity, without which Christianity has no reason to exist. For purposes of this question I'll call them 'extreme liberal Christians'.
To those of you who think that this "extreme liberal Christians" group doesn't exist, or is poorly defined, let me say that no, this group really does exist, and is pretty easy to check whether one belongs to this group or not. You can read more about the view of this group of Christians here, and read a conservative theologian debate with a liberal one here. And yes, everyone out there calls them "liberal Christians" freely. I just can't understand why mods here can't understand this term properly.
Back to my main question.
As I see it, if one doesn't believe in Jesus is the only path to salvation, then what is the "selling point" of Christianity? Why should people bother to become Christians at all? It would be equally OK to be a(n) atheist/agnostic/Buddhist who believes in Jesus as a great teacher and religion leader but not more.
By similar token, if extreme liberal Christians deem that Bible is just another book, written and compiled by mere humans with human errors in it, then it is no longer infallible and there is no reason to mind Biblical teachings in any matters. What is the difference between extreme liberal Christians and non-Christians? And non-Christians can draw inspiration from the Bible just as in the same way as those Christians do. They believe in exactly the same thing!
I don't mean to ask this in a provocative and confrontation way, but I am curious on what basis do extreme liberal Christians identify themselves as Christians?