Again, circular argument. You are making a retroactive presumption to “prove” your argument. That’s a fallacy.
You don’t understand truly accepting Jesus if we go by your first line of “reasoning”. I would recommend it, though.
We are talking of Faith, which itself is tautologically challenging when we derive arguments from scripture to counter arguments. Zin Girl was deriving arguments from a book and orthodoxy of faith. “The classroom rules” of logic and reason course 101 don’t necessarily apply here and only God can rule on what is “fallacy”
1 John 2:19They went out from us, but they were not of us; for if they had been of us, they would have continued with us; but they went out that they might be made manifest, that none of them were of us.”
Perhaps you would like to accuse John of uttering a logical fallacy.