Acharya Prashant explains that the fear mentioned in the Guru Granth Sahib is the fear that accompanies profound love. He clarifies that while love is often associated with fearlessness, it also brings a great fear of not uniting with the beloved. This fear is the source of immense energy and restlessness, as the lover's center of life shifts from themselves to an external entity. He describes this state as having one's heart in someone else's hands, leading to a sense of urgency and a desire to reach the destination quickly, much like the movement of wind or rivers.