Did you personally witness the writing of either? If not, what makes you accept them as authentic documents?
There is the rub (sorry, could not resist). It is possible that the works attributed to the people we associate with them are incorredctly associated.
Shakespear
most likely did write his plays but we have to be open to the outside chance that old Bill was some chancer who appropriated the associations we have with the plays.
As this is the case we cannot say for 100% that the biblegod is true.
Having no doubt (i.e faith) in spite of the (potentially small) chance that biblegod is not really real must lead to dissonance unless one is (as mentioned above) one who thinks all contra indications to biblegod's veracity are irrelevant.