For believers, if God uses the Bible to communicate factual information, then why four gospels? And why are they not in harmony with each other? Why not send down one record of the life of Jesus as it really happened? Is this in itself a form of revelation by God of the nature of the Bible?
For non-believers, why did early Christians not restrict the canon of scripture to one account, so opposers would have less ammunition? And why would they allow so many inconsistencies to remain in the Bible?
JWs and others want the Bible to contain one accurate and agreed account of what happened, but it does not. It contains errors, contradictions, and mistaken teaching in some parts, that gets corected or resolved in some way elsewhere.