That process is described in the Bhagavad-gītā: bhaktyā mām abhijānāti (BG 18.55). Kṛṣṇa, the Supreme Personality of Godhead, He says, "If anyone wants to understand Me, then he has to take the process of devotional service," not by the speculative process or by And it is the Lord, out of His causeless mercy, who sends His most confidential servitor to this world to instruct pure devotional service.
By the divine grace of the spiritual master, the seed of pure devotional service, which is completely different from the seed of fruitive activities and speculative knowledge, is sown in the heart of the devotee. Then, when the devotee satisfies the spiritual master and Kṛṣṇa, this seed of devotional service grows into a plant that gradually reaches up to the spiritual world. An ordinary plant requires shelter for growing. Similarly, the devotional plant grows and grows until it takes shelter in the spiritual world, without taking shelter on any planet in the material world. In other words, those who are captivated by pure devotional service have no desire to elevate themselves to any material planet.