Very good question! I commend you for your eagerness to be informed.
The bible is a formalized compilation of a collection of various books, written over hundreds of years in various cultures, and different interpretations of Christian themes. This was officially carried out by Emperor Constantine, at the Nicene Council, approximately 325 A.D. The council was an assembly of various experts and authorities, who may largely disagree, but were capable of agreeing upon what was acceptable as the formal canon. Some books were selected over others for arbitrary reasons, but the idea was to come to a common resolution on what is central to the Christian faith.
Although, you may not find many followers who are willing to admit it, we know that the bible has been alter altered, over the course of almost a thousand years, because their are very different translation and versions, that are a result of intentional and unintentional factors. Most people cannot get over there own bias that confirms what they want to believe, either in rejecting errors are present, or accepting that they were intentional, therefore the faith is "false." Mistranslation, misinterpretation, misconception, influence and control, are all flawed traits of humanity, which are plausible explanations for discrepancies found upon examination.
In the King James version of the Bible, translated from Greek, Jesus is quoted as saying, "God, why has thou forsaken me?" It is puzzling why a Spiritually Advanced being, said to be closest to God than anyone, would say such a thing without explanation. In the Lamsa Bible, from Aramaic, the language Jesus spoke, Christ say, "My God has not forsaken me, from this, I am spared." The interpretation makes a whole world of a difference in following in a faith that tells us our Immortal Souls are on the line. Overall, I am of the belief that all this is a consequence of the Western European "white supremacy", that rejects and denies anything out side of it's realm of familiarity.
In Eastern cultures, the varience and discourse are not so pronounce as is in Western faiths. Their cultures and religious/spiritual customs have been long preserved, for hundreds of years, long before Western civilization's rise to prominence. The European influence over the last 2000 plus years has lead to much conflict (which seems to be an expression of their violent origins, fighting for control over territory and resouces in a barren environment), which is why the subject of Western faith is so confusing. "Taking" over "producing" had to become the way for survival, which also depends on imposing oppression on those who think differently.
In Western society today, both believers and non-believer seem to faith and religion to officially start with Judeo-Christian beliefs, and many atheist are prone to portraying religion in general, to their own limited understanding of Christianity and it's history. Even though, historically, it has been exposed that Jesus came from a region where whites were not common, it hasn't stopped white Christians from portaying Him as such, which consciously or unconsciously promotes the "white supremacist" mentality in the world. All other religions are typically passed off as "superstitious nonsense" practice by unsophisticated tribal peoples dancing around a fire in loin cloth."
As Western dominance advanced, becoming more superficial and materialistic, it subscribe to ideas that disregard and even violated the natural progression of nature, which has seeped into various other world culture who've had a tradition of using nature as a guide. With some reluctance, ethnic non-Europeans had eroded their spiritual ties for worldly and material conforts and conveniences that appear to be superior to more primitive and outdated ways. Secularism, due to a more mechanistic understanding of our world, has much to do with how Westerners view religious and spiritual matters.
It is from this mentality that people are commonly lead to believe God and religion are manmade concepts, based off of our human limitations and flaws. There may be some degree of truth to that conclusion, but it seems to be an oversimplification and not a well thoughtout postulation, given to the mass lack of education on religious and spiritual themes, which are usually taken out of context infavor of a neatly package material explanation. Unto themselves, by the meaning of their original intent, non-Western faiths prove to be very sophisticated and much in line with modern Western discoveries in science, which are milinena behind the curve.
The lack of understanding of mysticism by the masses, who have no experience or understanding to go off of, results in anthropomorphic depictions of divine figures that end up not representing Divinity at all, based off of ego projections. The gaps are filled in worldy explanation for occurences that are so evident, which has perpetuated a more fearful mentality of the supernatural, rather than a more benign representation Advanced Mysticism offers. It is through the comprehension of mysticism, which transcends, culture, time period and geographic location, that the Reality of God can be properly understood through a worldly filter.
The idea of an undetectable omnipresent, omniscient, and omnipotent presence, is far beyond the intelligence level of the largely illiterate and uneducated masses who project and overactive imagination onto the world, let alone some highly intelligent person that figures things in a material sense. The existence of anything outside of the sense of the finite cannot be manmade and can only come from a Divine Source. Man is not programmed to think outside of a finite sense, if so it WOULD be "material evidence of the existence of God", which paradoxically disproves the existence of a God that cannot be proven or disproven.