Up to a point you are correct. Beyond that point you are completely wrong. Yes, the Bible was written over a period of about 1,500 years (give or take a few years) by about 40 different authors. Moses, who lived about 1400-1500 years before Christ wrote the first five books (sometimes called the Pentateuch). After that Joshua, Samuel, David, Solomon, and various scribes and prophets wrote the rest of what we refer to as the Old Testament. In about 1948 the Dead Sea Scrolls were discovered. These are copies of most of the Old Testament Scriptures that date to about the time of Christ (about 2,000 years ago). What we have in our Old Testament Scriptures today is virtually identical to what is in these scrolls.

There is a "gap" of about 400 years or so between the end of the Old Testament and the beginning of the New Testament (Malachi - Matthew). It was during those years that the Greeks (primarily under Alexander the Great) rose to power. The Greeks were then succeeded by the Romans, which is the government we find in power in the New Testament.

The New Testament was written by the apostles Matthew, Peter, John, and Paul, along with James and Jude (half brothers of Jesus), Luke (traveling companion of Paul) and Mark. The only New Testament book whose authorship is in doubt is the book of Hebrews, but most believe it was written by Paul. I have my own opinion about that but that's another discussion.

As far as the authenticity of the New Testament is concerned there are literally thousands of ancient manuscripts attesting to the accuracy and authenticity of the New Testament. Yes, I know that there are those who claim that the text has been "corrupted" due to differences in the various manuscripts that have been found. However, it should be noted that the vast majority of those "differences" are differences in spelling, grammar, and other similar things. The actual doctrines taught remain the same.

One thought on Bible translations: One poster stated that someone (I don't know who) had stated (or at least implied) that the King James Version of the Bible was straight from God. While I do regard the KJV as a good translation I would never maintain that it is the "best." The Bible was originally written in Hebrew (OT) and Greek (NT) with a few sections in Aramaic. Anything you read in English or any other language is a translation. As with any document or statement, when you translate from one language to another you will encounter certain problems since there is not always a word-for-word equivalence. Keeping that in mind is always a good thing to do when studying the Bible.

Final thought: the Bible claims to be "inspired" (God-breathed) by God (2 Timothy 3:16, 17; 2 Peter 1:19-21). Unless that is true how could so many different authors, living in so many different places, separated by so many years have written something in which there are no contradictions, no provable scientific or historical discrepancies, and have stood the test of time as has the Bible? François-Marie Arouet, known by his nom de plume Voltaire, predicted in 1776, “One hundred years from my day, there will not be a Bible on earth except one that is looked upon by an antiquarian curiosity-seeker.” Within fifty years after his death the house where he lived and the printing presses he used to publish his writings were being used to print and store Bibles and other religious literature.   https://crossexamined.org/voltaires-prediction-home-and-the-bible-so...

For further study concerning the accuracy and authenticity of the Bible I recommend "How We Got the Bible" by Neil R. Lightfoot (published by MJF Books, copyright 2003), as well as anything written on the subject by Jack Pearl Lewis (now deceased).