Srimad-Bhagavatam: Canto 10 - Chapter 1 - Verse 25
आत्मानमेवात्मतयाविजानतांतेनैव जातं निखिलं प्रपञ्चितम् ।ज्ञानेन भूयोऽपि च तत् प्रलीयतेरज्ज्वामहेर्भोगभवाभवौ यथा ॥ २५ ॥
ātmānam evātmatayāvijānatāṁtenaiva jātaṁ nikhilaṁ prapañcitamjñānena bhūyo ’pi ca tat pralīyaterajjvām aher bhoga-bhavābhavau yathā
A person who mistakes a rope for a snake becomes fearful, but he then gives up his fear upon realizing that the so-called snake does not exist. Similarly, for those who fail to recognize You as the Supreme Soul of all souls, the expansive illusory material existence arises, but knowledge of You at once causes it to subside.
Those submerged in illusion see material existence as infinite, just as one who is submerged in water sees only water all around him. For example, material scientists and philosophers, submerged deep within the ocean of material illusion, imagine that material nature extends infinitely in all directions. In fact, the material creation is a finite ocean of ignorance in which foolish living entities, such as material scientists, are unceremoniously dunked by the order of the Supreme Personality of Godhead. To be trapped in a world in which all things are born and die is certainly a fearful experience. Anyone trapped in a dark place naturally becomes fearful. Since material life is always covered by the darkness of ignorance, every conditioned soul is fearful. The material nature is not ultimate reality, and thus analysis of matter can never provide answers to ultimate questions. This dark, snakelike existence called material life immediately disappears as soon as one opens his eyes to the bright light of Kṛṣṇa consciousness.