why should we believe

[C]an you give me any reason why we should believe the Bible is true in the first place?

Or, more simply...

Why should we believe the Bible is true?

And that question really boils down to

What is truth?

We might think that only a brilliant philosopher would dare wrestle with this puzzle of a question. But it really doesn't take a "rocket surgeon" to answer the question:

Truth is what corresponds with reality. So, what is real is true. What is unreal is untrue.

The Bible makes numerous truth claims, among them: God exists and God created the universe, God communicates with us (his creation) through our moral conscience and the Bible, Jesus claimed to be God in the flesh, and so on.

These claims that the Bible makes either correspond with reality or they do not.

Christians believe the claims the Bible makes correspond with reality, so, they believe the Bible is true.

Their belief is supported by physical evidence: copies of copies of manuscripts that show the Bible has been preserved and transmitted accurately through history. The internal consistency and coherency of the Bible also attest to its claims, and its consistency with archaeological finds is also evidence.