True for you, true for me, truth about truth

I have a friend who is friends with an old lefty Catholic former professor of his. The professor doesn't believe some of what the Church teaches and of what my friend does believe. So he tells my friend, "what you believe is true for you" even though, he also claims, it's not true for other people. So for other people the opposite "truth" is true, that is, it's "true for them." But here's the truth about truth and this kind of "truth" talk:

"It's true for you" almost always really means "you think it's true; but in reality it might be false." (And it almost always means this as a matter of semantics, i.e., the logic of the language, regardless of the speaker's explicit intention, or attention, or advertence to this logical reality.)

So "it's true for you" doesn't mean "it's true" at all. In regard to truth itself, it really just means "either it's true or it's false."

If that is well understood, then "it's true for you" can be an innocent facon de parler (a "so to speak" kind of thing).

But in its usual usage, it's deployed as a way of ignoring (or pretending to ignore and attempting to bury) the real meaning of "it's true for you," and thus as a means of ignoring (or pretending to ignore and attempting to bury) the real distinction between "it's true" and "it's false" (i.e., between truth and falsity). So "it's true for you" is usually really a means of ignoring (or pretending to ignore and attempting to bury) the real distinction between reality and fiction, the real distinction between the truth and a lie, and the real distinction between what is good and what is evil. And so usually when you hear someone pull out the claim "it's true for you," be forewarned: what you're dealing with may be innocent confusion, but is likely duplicity and hypocrisy at a deep-rooted level. It is effectively, if not intentionally, a foundational attack on our ability to rightly understand anything. It's a faux-inclusive rhetorical move that actually excludes everybody, because it systematically misconstrues everybody's claims, that is, the claims on all sides of a given debate.