Acharya Prashant distinguishes between the concepts of immersion and alertness, explaining that they belong to different spiritual terrains. Immersion is the advice given to the ego in relation to the Truth. He describes the ego as a small, dirty lump that needs to be cleaned by the vast ocean of Truth. True immersion requires total contact with the Truth alone, excluding everything else, much like a diver who is completely surrounded by water rather than a swimmer who remains in contact with the air. He further refines this by using the term 'marination,' where the Truth penetrates the core of the individual, leading to the dissolution of the ego's littleness and impurities.