If it somehow turns out that we Biblical Universalists are wrong about the interpretations of Scripture that led us to believe everyone will be saved (along with the other related doctrines we hold to), it’s entirely the fault of Christians for not showing us where we went wrong in those interpretations (at least from a relative perspective anyway; I realize that God would ultimately be responsible from an absolute perspective).
And for those Christians who think that just “proof texting” the passages they assume prove Infernalism or Annihilationism is good enough, we Biblical Universalists already believe every one of those passages, just as we do every passage of Scripture; we just believe they mean something different from what Infernalists and Annihilationists assume they mean, thanks to years of careful and in-depth Bible study. This means that, if some Christian doesn’t learn our interpretations of these passages and show us why our interpretations of said passages are incorrect, they haven’t done their job of correcting us yet (presuming we are wrong, of course). The problem is, so far literally zero Christians have actually dealt with the actual scriptural interpretations of those passages that we hold to (or of the passages we use to defend Biblical Universalism itself either, for that matter). I know some Christians think they have, but I’ve searched far and wide for a single refutation of the specific interpretations we hold to when it comes to the relevant passages of Scripture, and I haven’t been able to find even one.
So if you’re a Christian who believes we’re wrong about Biblical Universalism, you can’t just expect us to take your word for it that we’re wrong, or simply quote a few “proof texts” as though we don’t believe them already. Because if we are wrong and you can prove it, you’re almost certainly going to be held accountable for not actually learning our interpretations of the relevant passages and showing us how our interpretations are incorrect. As for how to do so, you can find all of our interpretations of said passages here: Biblical Universalism