Okay, now I'm confused. Didn't you say in an earlier post somewhere that you considered the Bible a product of a human with an agenda.
In any case, your statement above is pure epistemology. I now understand you to say that your source of truth is the Bible. This is the center piece of the protestant reformation, Sola Scriptura.
Now we have to go one, and determine how we arrive at the interpretation of scripture. It's a Science
called exegesis, from Greek ek=out of and ago=to lead. It means to lead out the meaning of the text.
Oddly enough, you can get 20 scholars/exegetes from 20 church traditions and they will all agree what the text meant to the author and the recepients.
What they will disagree on is authority. Is the Bible, correctly interpreted by sound historical and exegetical method, the only authority? That's the conservative protestant position. Or is reason, rationale the final arbiter of truth? That's the liberal protestant tradition. Or is the Church and tradition the final authority (Her spokespersons and clerics). That's the Roman Catholic position.
There are plenty of other positions. The aethiest appeals to the scientific method. But Science
can only be agnostic. It's impossible to argue that there is evidence that God does not exist, one simply cannot know from the scientific method because the "supernatural" is not available for scientific investigation. That's why is called Super, beyond the natural.
That's why my previous posts on epistemology and authority. Now I can have a conversation with you.
We can discuss from the Bible, and I am an exegete and can provide the agreed upon meanings of biblical passages. And there are some disagreements of course, but not on the substantive issues of Christianity.
If you're Muslim, then your authority would be the Quran, and possibly a particular contemporary teacher or sect.
And on it goes.
How do you know? God has revealed Himself and His truth in the Bible.
Do you accept the Bible, rightly interpreted, as the final authority in matters of faith and practice?
These are the foundational issues. We cannot have an intelligent disussion until everyone "comes clean" on epistemology and authority. Only then do we know why we agree to disagree.
This should provide fodder or grist, depending on your viewpoint.