That would be throwing the baby out with the bath water.
Christianity does not stand and fall on the behavior of those who claim to be Christians.
The gospel is true because it's of GOD and it will continue to be true even when people are not.
And what some see as *Christianity collapsing*, others see as the death throes of sterile religiosity or a purifying of the church as God sifts out the chaff and tares from the wheat.
Romans 3:3-4 What if some were unfaithful? Does their faithlessness nullify the faithfulness of God? By no means! Let God be true though every one were a liar, as it is written, That you may be justified in your words, and prevail when you are judged.
How do you know it is "of GOD?" Because it wound up in the King James Bible and it wouldn't be there if it weren't?
It isn't authorized by the Torah and therefore is illegitimate and no different than any other later made-up religion.