The question of the Bible and its reliability is a loaded question. Is the Bible reliable? The short answer is yes. The long answer is nuanced and revolves around many satellite issues of what the term reliable means.
Reliability and the Autographs
For example, is the Bible reliable because the Bible we have today may differ from that of fifteen hundred years ago? Fortunately, we can easily answer that question. Enough archaeological remains of Biblical texts exist that seem to point to singular source texts (or autographs).
Much of the autographs can be restored from the Dead Sea Scrolls, Masoretic Text, Samaritan Pentateuch, Septuagint, and the thousands of New Testament manuscripts and fragments. And even with unresolved variants, what variants do exist do little to change the meaning of the text. Many of the variants are attributable to spelling mistakes, transposition errors, or accidental deletions caused by, for example, same endings (homoioteleuton).
Although we can point to a Biblical autographic text, the question of reliability is far from answered. If by reliable we mean that the Bible accurately reflects our understanding of what it means, the answer is a qualified not necessarily. A lot of traditions and beliefs have been superimposed over the Bible. These traditions may not necessarily reflect the way the original authors would have read the text.
Reliability and Literary Style
The Biblical authors used many literary devices that might be unfamiliar to the modern reader: retrojection, cyclic parallelism, and gematria. Such devices were obvious to ancient readers but to us are a missing piece of the context.
For example, many people assume that Moses was a prince (“son of the king”) because his adoptive mother was the daughter of the king (Exod 2:5). From the archaeological evidence, no reason exists to believe that Moses ever held that title or lived in a palace. In all likelihood, the title was given to Moses’ adoptive mother retrojectively after her father assumed the throne and probably long after Moses had fled Egypt. But if we read meanings into the text that are not actually there (eisegesis), can we make the claim that the Bible is unreliable when those meanings don’t pan out? Unfortunately, this happens far too often.
Now, what if by reliable we mean that miracles happened and God appeared at certain times and places? Possibly, but this is generally impossible to prove on way or the other. Miracles and divine manifestations might leave physical after effects. But how can one distinguish such effects from other physical phenomena? One could suggest that the improbability of Israelite survival infers divine intervention, and it may. However, this would only show that events like those described may have occurred, and therefore does not address reliability one way or the other.
Morality, Science, and History
What if we mean that the Bible is reliable for ethical and moral teaching? Quite likely, since much of the functioning ethical systems of the world do reflect a Biblical origin. Do not steal and do not murder remain universally good ideas. Loving your neighbor is also an ethical good. Some areas are gray; however, it seems some of the grayness often arises out of reading a passage out of context; for example, reading ritual laws as ethical imperatives.
What if we mean that the Bible is reliable scientifically? Yes and no. Again, context matters. Some passages are not meant to be read as factual accounts or use definitions that have changed over time. Applying a strict scientific idealism to an ancient text is anachronistic. For example, sometimes a “year” was not exactly 365.25 days, and thus does not reflect an exact solar revolution around the sun.
Even the lower standard of does the Bible line up with “facts” can present a problem. This is because what constitutes a fact can often be in the eye of the beholder. For example, how years were counted in the books of Kings changed to reflect the shifting hegemony of Egyptian and Assyrian suzerains. The Bible might reflect a political reality where a Western reader may expect a scientific reality; this is not a problem with the text as much as the reader’s expectations.
Is the Bible Reliable?
So can we say that the Bible reliable? I think that this depends largely upon our approach to ancient texts. We could read the Bible in its context. We could present the Bible as it represents itself. And we could treat the text without special prejudice just like we would any other ancient Near Eastern text. If we approach the Bible in that manner, we can definitely glean historical information from it. And that historical information has been confirmed by a large amount of secondary sources, e.g. the Sennacherib Historical Prisms (see featured image above) confirming the siege of Jerusalem. Insofar as taking the Bible from a historical point of view, I have no doubt that the Bible is reliable.