Having a god and swearing on the bible are two separate things. The former indicates having a faith, the latter indicates one can recite a paragraph with ones hand on a book.
I think people with religious beliefs get worked up about such things a lot less than those who take them with a large pinch of salt.
The one time l swore on a bible l regarded it more as an act of symbolism than anything else - it would have been a waste of my time and energy to try to score points for my "side".
On a personal note, the act of swearing on a bible to become a mason, or to join any club, is so absurd that if l had my good enough reason to join said club ld go along with it - its not like it means anything.