The larger part of the Bible is of Jewish origin a.k.a the Old Testament.
I would argue that 100% of the Bible is of Jewish origin, but that probably not the point you were making.
:)
This is true. I suppose the obvious point is that when one chooses to swear an oath of office on the Bible, one is acknowledging the Judeo-Christina heritage of the nation. Swearing the oath on the koran signals something very different.