The first thing that'd be helpful to understand is that accepting what the Bible, or any other text, has to say, is not an all-or-nothing deal.

It could be that a book makes 10 claims, and only 7 of them are correct. How would we know which are true, and which are false, outside of independently validating each one?

The same applies to the Bible.

Clearly, Egypt existed, and so did some other cities mentioned in the Bible. Thus, we'll believe those specific claims. When it comes to the notion that a person was the son of a god, and performed miracles, those claims earn no credibility simply because other assertions in the same book (the Bible), happen to be true.

Those miracle/god claims would need to be independently validated. The parts of the Bible we don't believe, we don't believe due to insufficient evidence.