Biblical Oath

Regarding the practice of swearing an oath on the bible in a court of law it would seem only natural to refer to the attributed words of the central human figure in that book, he being Jesus:

I say unto you, Swear not at all;
neither by heaven; for it is God's throne:
Nor by the earth; for it is his footstool; neither by Jerusalem...
Neither shall though swear by thine own head, because thou canst not make one hair white or black.
But let your communication be, Yea, yea; Nay, nay: for whatsoever is more than these cometh of evil.

So it is perfectly clear that to swear on the bible is an absolute transgression of the book, and that in essence the word of anyone under oath to the bible is according to Jesus' words intrinsically worthless and a mockery of that book in its Christian essence. Given that the legalistic world is supposed to excel specifically in its use of logic this is all so blatantly obvious that it's hard to understand what to make of it. The obvious implication is that all testimony in all court cases so far taken under biblical oath should be struck out as inadmissible.