Acharya Prashant defines a scripture as any book that discusses the dissolution of the ego into the Self. He clarifies that useful books on worldly subjects like engineering, medicine, or astrology should not be called scriptures, as the true subject matter of a scripture is only the Divine or the attributeless reality. He emphasizes that terms like 'Vastu' or 'Jyotish' are incorrectly labeled as scriptures. Authentic scriptures include the Upanishads, the words of saints, the Bible, and the Guru Granth Sahib, because they focus on attaining the Truth. He warns against treating any book as a scripture just because it is useful, noting that while worldly books have their place, the term 'scripture' is a high designation reserved for texts that lead to spiritual liberation. Regarding mantras, Acharya Prashant explains that a mantra is a profound truth expressed concisely and clearly. A mantra must be understood to be effective; mindless repetition of sounds without knowing their meaning is futile and becomes a burden of the ego. He dismisses the idea that mantras work through mere 'vibrations' or 'sounds' without understanding, asserting that Truth is of the nature of consciousness and requires comprehension. He also explains that a Guru provides a specific mantra as a medicinal remedy tailored to an individual's mental state. The purpose of a mantra is to act as a 'shield' that one must wear constantly, especially during moments of internal conflict like anger or lust, rather than remembering it only when one is at peace. He further distinguishes between different forms of spiritual practice: 'Bhajan' involves loud singing and music, 'Jap' is closer to silence or whispering, and 'Simran' is complete internal silence. 'Kirtan' is the most expressive form, often involving group dancing and instruments. Despite these outward differences, the central goal of all four is to maintain the company of the Divine. He clarifies that while the purity of pronunciation was historically important for oral preservation of texts, the essence lies in the meaning and the transformation of the mind. He concludes that studying multiple scriptures is often necessary because most people are not alert enough to grasp the Truth from a single statement, though for a truly ready seeker, even a single word like 'Om' or 'Satnam' is sufficient.