BG Chap 15 - The supreme position of bhakti
Although the one sac cid ānanda form of the Absolute Truth is called by the names Brahman, Paramātmā and Bhagavān, actually there is no difference between them. However, because of observing difference in the worshippers, in terms of sādhana and the results, difference has been designated. The sādhana respectively of the jṇānī, yogī and bhakta produces realization of Brahman, Paramātmā and Bhagavān. The result of jñāna and yoga is mere liberation, and the result of bhakti is to become an associate of the Lord with prema.
Without bhakti, the jṇānī and yogī do not attain liberation. This is confirmed in Bhāgavatam 1.5.12, where it is said that knowledge of self realization, though free from all material affinity, does not look well if devoid of a conception of God. And in SB 10.14.5, it is said that in the past many yogīs achieved the platform of bhakti by offering all their endeavors unto Kṛṣṇa. Thus the worshippers of Brahman and Paramātmā must necessarily perform bhakti to Bhagavān to achieve the final results of their sādhana. The worshippers of Bhagavān, however, do not perform worship of Brahman or Paramātmā to achieve the results of their sādhana. This is confirmed in SB 11.20.31 where it is said that for a devotee engaged in loving service to Kṛṣṇa, the cultivation of knowledge and renunciation is generally not the means of achieving the highest perfection. Thus by worship of Bhagavān, it is possible to attain all results: material enjoyment, liberation and prema. But by worship of Brahman and Paramātmā alone, it is not possible to attain enjoyment, liberation or prema. Therefore, it is said that Bhagavān is in a superior position even though He is non different from Brahman and Paramātmā. It is just like a huge fire is superior to a small light and a lamp because of its superior ability to alleviate the pain of cold even though all of them are essentially the same energy.