But if you're trying to prove that you don't need to invoke the Bible to have a conversation, you can't invoke the Bible in that proof.
A first question is ... why can't you?
And a suggestion is that ... yes you can!
If you understood the dirty little secret about how and what we know - it's all built around axiomatic frameworks that demand your compliance and understanding of the framework to begin explaining you how things work using language of the framework.
For example, here's Richard Feynman explaining how magnets work:
He can't explain it apart from scientific axioms, which are rather nominal in that case. He just names that repelling force to be a magnetic force, and off it goes... and of course he gives a lengthy background as to why all of the explanations rest on the continuum of dependent explanations.
Yet, in the end, what it boils down to....we can measure ratios, and we can use these ratios in some functional setting to build tools. Most of the stories we tell about all of the "wonders of the universe" are just that... stories to give some narrative to numbers. But, those stories formulate the conceptual frameworks that are used to communicate certain models of reality. And the point that Feynman is making is that you can only explain certain aspect of the framework using the other aspects. You can never explain these in isolation, or using linguistic concepts that wouldn't apply.
Thus, your expectations in that regard are just as irrational as expecting a physicist to explain physics without making appeals to axioms of science. It's an absurd expectation. Christian framework formulates different first assumptions, and these assumptions are pre-requisite for you understanding the claims of the framework. You are free to make different assumptions and tell a different story, but you would still invoking self-referential concepts to validate various premises that you hold.
So, if you demand falsifiability, we have to first break down who made that rule, and why you have to invoke that as a rule to follow. Because, eventually it all boils down to "I have no proof, but things seem more coherent to me this way", and essentially that's what it's all about. It's not about a proof, but about presenting a coherent framework that can serve as some web of reference for human experience.
So, perhaps a question for you would be about what you expect as a behavior for a Christian in that context, and why would you think it would be correct? But, here's a request, since you are on Christian forum, please don't invoke secular axioms, until you provide a definitive proof that your axiomatic assumptions are valid.
