If that text book is all you have, and there is no other evidence, then it makes sense to be skeptical.
Like “Howard Zinn’s Peoples History” skeptical.
People are always ready to write their today motives into historical persons, or legendary persons.
The difference between history and legend is the history has facts, evidence, and reason to back it up. Legend has a story, but the facts are either impossible to find or impossible to believe.
Ah, yes, but we DON’T have just one text. We have many texts, all proclaiming the same message, with just enough differences between them to discount collaboration and conspiracy between the authors.
We don’t have the original documents of many of the early founding fathers either. They were destroyed or rotted away or were lost. But we have copies of them, and copies of copies, and copies of copies of copies, and we still tend to agree that those were what were on the original papers. Sure, some copies might have spelling errors or translation errors, but the same message is still there.
So why can’t we believe that what was written in Scripture accurately reflects what was originally written?
So; even with FACTS; you'd find a reason not to believe.
I think I'm beginning to understand.