The Gita offers a comprehensive account of the two basic forms of worship: meditation on the unmanifest form of the Lord known as Nirguna or Akshara Brahman and on the His manifest form, with attributes and auspicious qualities, known as Saguna Brahman.
Krishna dwells at length on matters such as Brahma Tatva, the state of Yoga Nishta, Vibhuti yoga, Viswarupa yoga, and so on, right from the second chapter to the eleventh and asserts that meditation on Nirguna Brahman is capable of granting Moksha. Then when He reveals His cosmic form to Arjuna, the Lord highlights the worship of the Saguna Brahman and states that His bhaktas are also able to reach Him. So Arjuna wishes to know which of these upasanas is better and which is to be adopted, pointed out Sri K. Ramasubramania Sarma in a discourse.
Krishna makes it clear that both types of upasakas are equally qualified to attain Him if single-mindedness is the basis of their worship. Nirguna Upasana implies an aspirant who perceives the oneness of creation behind the diversity, who transcends his attachment to the body and the pulls of the senses and is always compassionate to all objects and beings. The Saguna upasaka is drawn by the Lord’s auspicious qualities and form and develops unswerving devotion to the Lord. But the efficacy of devotion is determined by bhakta’s ability to dwell on the Supreme Brahman at all times, and by dedicating his thought, word and deed to Him, whatever may be his form of worship. When one’s mind and heart is filled with desires and one’s attention is diverted by the senses and emotions, and one yields to selfish longings that do not allow him to be considerate towards others, his meditation is of no use. This applies to any upasaka, the onus being solely on involvement, concentration, sincerity, renunciation and purity of mind.
