Ultimately, the centrality of the teachings of the Bible is a matter of faith. If one reads it, it is hard not to be moved by its message, given the age and overarching consistency of theme. However, the fact that it exists at all is a testament of its endurance; holy books of the Egyptians and Hittites and Atticans are not similarly venerated or even in tact in the way that the Christian Bible is.
There is, however, a fairly strong argument to be made in the failure of Christians in our era to behave like the Christ of our book. Really, it is an impossible task because the example we are held to is perfection, but we, inevitably, will not reach it. We are men, not Sons of God. That does not mean we should surrender. Faith without works is dead, you know.
Our failures are disastrous. They are poison. So we must endeavor to have successes to counter them. Love covers a multitude of sins. There is no shame in aiming for perfection and missing. The shame comes in not reaching it and being satisfied. Christ has bigger plans for us all.