From a purely scientific point of view, atheists argue against the existence of God because there is no evidence to support such a being. It is simply the nature of “belief” – and the reason why religion is still rife in civilized society – that a belief does not require proof.
But Christians argue: “Does the Bible not count as a source of verifying the existence of God?”
First of all, you must note the origins of the Bible. The writings which were eventually gathered together and came to be known as “The Holy Bible” were written over a period of 1500 years by more than 40 different authors living on 3 different continents (Asia, Africa, and Europe). The Old Testament is a collection of books, written primarily in Hebrew, with some books written in Aramaic, between 1400 BCE and 400 BCE.; the New Testament is a collection of books, written in Greek, between 45 A.D. and 95 A.D.
While the text itself was penned by the hands of its various human authors, Christians claim its origin to be divine. In some books, God speaks directly with His people; in others, it is claimed that the written words were inspired by God, without directly intervening.
On top of that, because the printing press was not invented until 1440 A.D., which means every word of the Bible was hand-written by scribes, each copying a previously hand-written document. Archaeologists comparing documents side by side find innumerable errors.
The way I would put it, the Bible (like other such texts) is best described as testimony rather than evidence. It claims a lot, but doesn’t verify a thing.
As a collection of texts ostensibly written as non-fiction, the Bible counts as a set of historical sources. As evidence, however, it is circumstantial at best, and simply not at worst. It’s difficult to impossible to verify the realistic-sounding events, let alone the supernatural ones.
Look at it this way: Christian say outright that God exists because the Bible says what it says. I’ve read the Bible cover to cover, and I ask why? Why, after reading that book, do you believe God exists when I don’t? Most argue that the Bible is true because of what it says in the Bible. Logically, that does not make sense.
Religious belief is just that: a belief. The Bible is certainly a historical document, but it is certainly not evidence to the existence of God.