But that is a whole new ballgame that you have introduced here because unlike you, we make no claims that the material world is deceptive so you cannot apply that criteria here. That can only apply to you.
That doesn’t make sense (never mind that you keep saying that they think the “material” world is deceptive–a term I haven’t seen Rossum use). Rossum is making an observation about reality. 100% certainty is not, rationally speaking, attainable about most things, including such questions as whether the Bible is reliable. That’s why Aquinas said that these things cannot be proven demonstratively–rather, probable reasons can be given and the certainty comes from the act of faith.
Rossum isn’t assuming Buddhist principles. He’s observing something about reality which fits his approach better than yours. Your approach and that of other very conservative Christians demands a level of certainty that is simply impossible, and so you wind up with continual cognitive dissonance that makes it hard to be intellectually honest.
We say we believe in the Bible because we believe that the Holy Spirit guided its writing.
I think this is a valid point, but I’m not sure Buddhists are actually saying that everything is deceptive in such a way as to make knowledge of truth impossible. That would make nonsense of Buddhist claims themselves. (One hindrance you face in understanding other religions is your willingness to assume that they are simply speaking nonsense, instead of trying to understand why people would believe something that doesn’t make sense to you.)
I do think that Rossum is making a distinction between ethics and doctrine that we Christians reject (and which I, like you, find unreasonable), as you pointed out above in the pink unicorn example.
Edwin