Bhagavad Gita, Chapter 4, Verse 40

The ignorant, the man without faith, the doubting self, goes to destruction. The doubting self has neither this world, nor the next, nor happiness.

Constant doubt doesn't protect anyone, it just quietly stalls a person out in every direction.

This isn't about punishing healthy questions, it's naming a real pattern: doubt that never resolves into either genuine trust or genuine understanding leaves a person stuck, unable to move forward or find real peace either way.