There is no way that the Hebrew Bible (aka the Septuagint, aka the Old Testament) is an historically accurate document. First, the Torah (aka the Pentateuch) is allegory and not written by Moses, who almost certainly never existed. The Documentary Hypothesis is the prevalent one on the Pentateuch (other than the silly, childish Biblical literalists -- yes, Michelle Bachmann and the tea party, I am casting my gaze at you).
The Christian New Testament fares no better. With just the four gospels there is the Synoptic Problem (Matthew, Mark, and Luke), the response to which is Markan Priority and the posited existence of a lost Q source(gospel).
I am not an expert on the Bible, but I try to educate myself about things that interest me. Biblical minimalism is intriguing. So is the entirely appropriately named Biblical apologetics.
If one is an atheist activist and one is ignorant of these things, one is just pissing in the wind.
I am probably still doing that. But at least I try.