Depending on how close and dear someone's belief are to their own identity, a context of warmth and growth could work against going against a wrong belief full-bore. Especially when you notice how essential such a belief is to someone's identity. Like telling a child there's no Santa, to their face.

rather than just looking for weak points in mine

Probably the crux of our disagreement: Looking for weak points in your own and the interlocutor's belief is what you should be doing, with as few distractions as possible. (If correct beliefs were the overriding goal. Which, all protestations to the contrary aside, they mostly aren't.)

However, I totally get that there are often more important things than correcting someone else's wrong beliefs. Such as building shared experiences, creating a sense of community et coetera. Singing Kumbaya ;-).