etad vai sraddhaya bhaktya
etat—this; vai—certainly; sraddhaya—with faith; bhaktya—by devotional service; yoga-abhyasena—by practice of yoga; nityasah—always; samahita-atma—he whose mind is fixed; nihsangah—aloof from material association; viraktya—by detachment; paripasyati—understands.
This perfect knowledge can be achieved by a person who is already engaged in devotional service with faith, steadiness and full detachment, and who is always absorbed in thought of the Supreme. He is aloof from material association.
The atheistic mystic practitioner of yoga cannot understand this perfect knowledge. Only persons who engage in the practical activities of devotional service in full Krsna consciousness can become absorbed in full samadhi. It is possible for them to see and understand the actual fact of the entire cosmic manifestation and its cause. It is clearly stated here that this is not possible to understand for one who has not developed devotional service in full faith. The words samahitatma and samadhi are synonymous.
Link to this page: https://prabhupadabooks.com/sb/3/32/30