Dear Alexandru,
I find that many “historians” are handicapped in their methodology and their conclusions are less than logical. My favorite quote in this regard is from Jacob Burckhardt:
After a careful study of history, we see that man has rarely learned from studying history.
Burckhardt’s methodologies have helped me to understand history in a different way that you have described above. The work done by Origen of Alexandria (185 - 254 AD) on the Hexapla showed how the inspired works were rewritten by the priests and scribes over time to conform with their experiences in Babylon, the city of the devil. This once spiritual document suffered greatly at the hands of politics.
The NT suffered the same fate. The only full version of the Bible comes from the fourth century. We only have mere fragments of the original writings, demonstrating falsification and error by omission in the Codex Sinaiticus.
In essence, the historians you reference are correct that the Bible was written for political purposes, but they do not understand the methods by which it was accomplished. This does not do justice to the validity of the original texts, before they were perverted by power-hungry individuals.