What can you mean by, "We do not know who wrote it." Of course we don't know them. They are long gone.
We do know, however, that the Bible was barely changed. The Dead Sea Scrolls show that the variations are minor, even from the Bible of today.
The Roman Catholic Church doesn't maintain the Bible. God does.
The Bible "copies" that have been changed by people to use false writings to control people, have fallen away. Just because science (which many people worship) has changed greatly in the last 300 years, as shown by its writings, doesn't mean the Bible has. In fact the evidence of the "sameness" of the Bible is so much greater than that of scientific writings that it blows science right out of the water regarding accuracy.

I mean that we don't know who wrote it. nothing more and nothing less, but that's a huge thing all the same.
while the Dead Sea Scrolls may be the most ancient version we have of the Old Testament, we do not know when it was written, really ( the scrolls 300 BC-100AD most likely) or by whom, although it is assumed to be a copy of earlier texts in any case, so we don't know when it was originally written, or by whom, or what their motives were.
Further to that, the scrolls have nothing to do with what most people think of as the Bible, and what I was talking about in the first place, which is the New Testament.
I've simply seen too much manipulation by 'men of God' to think they didn't bend things more than a little bit when putting these materials together.
My mistrust of the media and politicians goes back well beyond the current era, as I do not think the crazy things we see today are new games at all, really. I think men are corrupt and will do anything to grab and hold power and I think that has always been the case.
There are three basic ways that I see that we can test how authentic the Bible is.
1. Read it and see how it makes sense (or not) regarding life. One need remember that the Bible was written for all people, but was also written for the people who lived at the times that it was written. Thus, it has many different customs and ideas in it that don't fit our times and customs completely, and certainly not exactly. Yet there is content that fits all human beings because all people are basically similar.
2. We need to look at the traditions of the nation of Israel regarding what they think about the Bible. When we do this, we need to know enough about this nation to see that they officially incorporate into "their" Bible, the Talmud and other writings, that we don't consider to be part of the Bible... and the whys for these differences. In addition, much of Jewry doesn't consider the New Testament to be truth at all.
3. Since most of us are not scholars of the history of the Bible, we need to see what the scholars say. We need to look at the real scholars, not simply the Internet scholars (like myself?) who produce second hand scholarly info, or who neglect the sense of the Bible in the documentation of its history. We need to examine the consensus of the best Bible scholars. And, that might take a bit of work.
My though is to read the Bible, especially the New Testament, slowly, not trying to pick it apart the first few times reading it, just to get the feel of what it seems to speak to one's heart. BibleGateway -
https://www.biblegateway.com/ - has loads of English translations and multitudes of other language translation so that one can read the Bible right online if so desired.

I've got no issues with people pointing to the bible or the Quran or whatever as a general guide for moral behavior, although that can be a slippery slope also, and leads to 'interpretations' that can often be nothing but manipulations to support a given viewpoint or purpose.
Anyhow, without getting to far into parsing any particular book, plenty of people would likely agree that the basic underpinnings of 'love thy neighbor' and 'don't kill that other guy', etc. are fine as generalities. I've got no problems there, and wish our societies could find some moral balance between "if you do that you'll burn in hell" and "there is no hell so I'll just screw everyone for my own benefit"
the problem for me arises when people point to it as "THE WORD OF GOD"- and this goes for all religions and holy books.
I think this is extremely dangerous for a lot of reasons, chief among them that we don't know that this or that is indeed the word of this God or that prophet instead of manipulations of some long ago A-holes that wanted to scare the crap out of people to keep them in line and/or subjugate them.
The other is that these things are then too easily manipulated, as there is no arguing "THE WORD OF GOD" taken from any holy book, even if it is batshit crazy. I guess what I'm driving at is that this sort of finality removes any common sense from any sort of analysis, which just opens the door on way too much manipulation by people that desire to manipulate others for their own ends.
Without conclusive proof then that this is indeed THE WORD OF GOD this takes this general guidebook for basically not peeing all over everyone else and turns it into what may arguably be the deadliest weapon in the history of the planet.