Acharya Prashant emphasizes that doubt is a valuable tool when directed inward toward one's own beliefs and convictions. He explains that doubt should target what we believe in, as it acts as a hammer that breaks down hollow or superficial beliefs while revealing what is truly indestructible. According to him, every belief is essentially a form of blind faith that must either collapse under scrutiny or evolve into true devotion. By questioning the foundations of our assumptions, we can move from a state of fragmented belief to a unified and authentic understanding. He suggests that once a belief survives the test of doubt, it becomes firm and no longer requires external validation.