A person who is in perfect knowledge of the Vedānta becomes a servitor of the Supreme Lord, who is the maintainer and sustainer of the whole cosmic manifestation. As long as one is not transcendental to the service of the limited, he cannot have knowledge of the Vedānta.
As long as one is within the limited jurisdiction of fruitive activities or is involved in mental speculation, he may perhaps be eligible to study or teach theoretical knowledge of the Vedānta-sūtra, but he cannot understand the supreme, eternal, transcendental (completely liberated) vibration of Hare Kṛṣṇa, Hare Kṛṣṇa, Kṛṣṇa Kṛṣṇa, Hare Hare/ Hare Rāma, Hare Rāma, Rāma Rāma, Hare Hare. One who has achieved perfection in chanting this transcendental vibration does not have to separately learn the philosophy of the Vedānta-sūtra.