Responding to Arjuna’s question about who are the best yogis—those who worship the Lord with form or those who worship the formless—Lord Krishna discusses forms of devotion (bhakti), their results, and for whom they are suitable (according to disposition of devotee). He extols the characteristics of the highest form of devotee and praises the knowledge they pursue.
An Audio Course on Vedanta Texts- Bhagavad Gita: Bhagavad Gita (Chapter 12) by Swami Tattvavidananda Saraswati.
