selected from purports of His Divine Grace A.C.Bhaktivedanta Swami Prabhupada
The living beings are all component parts and parcels of the Absolute Personality of Godhead, and therefore they are eternally related with Him as the servitor and the served. The Lord is served by all His parts and parcels, as the complete machine is served by its parts and parcels. Any part of the machine removed from the whole is no longer important. Similarly, any part and parcel of the Absolute detached from the service of the Lord is useless. The living beings who are in the material world are all disintegrated parts and parcels of the supreme whole, and they are no longer as important as the original parts and parcels. There are, however, more integrated living beings who are eternally liberated. The material energy of the Lord, called Durgā-śakti, or the superintendent of the prison house, takes charge of the disintegrated parts and parcels, and thus they undergo a conditioned life under the laws of material nature.
When the living being becomes conscious of this fact, he tries to go back home, back to Godhead, and thus the spiritual urge of the living being begins. This spiritual urge is called Brahma-jijñāsā, or inquiry about Brahman. Principally this Brahma-jijñāsā is successful by knowledge, renunciation and devotional service of the Lord. Jñāna, or knowledge, means to know everything of Brahman, the Supreme, renunciation means detachment of material affection, and devotional service is the revival by practice of the original position of the living being. The successful living beings who are eligible to enter into the realm of the Absolute are called the jñānis, the yogis and the bhaktas. The jñānis and yogis enter into the impersonal rays of the Supreme, but the bhaktas enter into the spiritual planets known as the Vaikuṇṭhas. In these spiritual planets the Supreme Lord as Nārāyaṇa predominates, and the healthy unconditioned living beings live there by rendering loving service to the Lord in the capacity of servant, friend, parents and fiancee. There the unconditioned living beings enjoy life in full freedom with the Lord, whereas the impersonalist jñānis and yogis enter into the impersonal glowing effulgence of the Vaikuṇṭha planets.
(Srimad Bhagavatam 1972 edition 1. 9.44 purport)