There’s a wide variety of beliefs, not every bible based religion has the same answer. Even within the same denomination, there are wide differences. For example, it’s been often pointed out that a US Roman Catholic believes different things than an Italian Roman Catholic.
Some take the idea that the bible are stories and parables rather than actual fact. Which means anything in the bible not supported by historical research can be hand waved away as, essentially, a non-factual morality tale. From a non-believer point of view, this is probably the closest to correct.
Similarly, there’s the claim that words mean something different to God. What he calls a day may be far far longer than what we call a day, so they argue God did create the universe and humans. He just did it through the big bang and evolution. I suspect this is a fairly common belief, at least in America. I know it’s the most common explanation I’ve heard from rational believers, as opposed to the mindless masses.
Speaking of the mindless masses, quite a few believe in the bible. Period. All that ancient history and fossils and evolution and so on are false trails to lead us down the wrong path. The world is 6000 years old, God made man, end of story.
And continuing with the mindless masses, most believers probably just don’t think about it. They believe the bible. They believe scientists. They never wonder how or why the two beliefs are somewhat contradictory. To use an Orwellian term, they believe in doublethink.
One of the more rational beliefs I’ve heard, although also probably the least common, is that God has updated religions several times. We should all know how Christianity is, basically, Judaism 2.0. Similarly, Islam is Christianity 2.0, as are some less popular religions like Latter Day Saints. I’ve heard arguments that God made revisions earlier as well, but we lost records of that over time. It’s even, very slightly, supported by the fact that parts of the OT seem to indicate other gods do exist, they’re just not as powerful as God. Which certainly can be read as God attempting to replace previous beliefs with new ones, in the same way Christianity ‘replaced’ Jewish beliefs.
Just for the record, I’m agnostic. There may or may not be a god, but I’m pretty sure none of the religions have it right. So none of the above are my personal beliefs, just things I’ve heard believers say.