The 12^th chapter is Culmination of middle section of Bagawad Gita, called madhyama śatakam.  Bhakti or love or devotion is possible only towards someone who is known.  Out attitude towards God will also depend on our knowledge of God.  Knowledge alone can contribute towards a healthy attitude.  Five chapters are devoted to give knowledge of God.  This 12^th chapter is the culmination of the previous five chapters.  In this chapter Lord Krishna has condensed entire vedantic teachings, both Veda Poorva and Vedanta concepts.  This chapter has two topics – bhakti yoga and bhakti yoga palam. 

This chapter begins with a question from Arjuna (verses 1 to 3), based on the previous chapter – viśvarũpa eeswara, which comes under saguna eeswara.  Arjuna has heard about nirguna eeswara also and he has a question of superiority of saguna and nirguna eeswara.  Generally, we are attracted to saguna eeswara because we are not capable of conceiving nirguna eeswara.  This question is relevant only when there is a question of choice.  In this case, there are no choices.   One must follow both saguna dhyānam and nirguna dhyānam.   Without saguna dhyānam, one can not come to nirguna dhyānam.  Without nirguna dhyānam, saguna dhyānam is not complete.  Nirguna eeswara is the ultimate reality. 

Bhakti yoga is not the name of a particular sadhana, but a range of sadhana that everyone must go through (Verses 3 to 12).  This range consists of five levels.

1. Sakama Karma Pradhāna Karma Yoga:  This is the beginning stage where a person is allowed to do any karma to fulfil personal desire.  For the maintenance of acquired karmas (yoga shema pradhāna karma), transfer some of the yoga shema to lord.  Then only we will have time for the other activities which is meant for chitha siddhi.
2. Nishkama Karma Pradhana Yoga or chitha siddhi pradhāna karma yoga.  Accept to live with whatever comes our way.

1 plus 2 is kama yoga.

• Ishta Devata Upasana:  Transfer yoga shema to lord, enabling the mind to turn inward, forgetting family, and other samsara.  In 12^th chapter, this is called abyāsaḥ yoga; look at ishta devata as viśvarũpa eeswara.
• Viśvarũpa dhyānam is aneka roopa dhyānam.  Once, I look upon as total universe, there are not many gods.  The Lord is not bound by any form, and this helps in the expansion of mind.  At this point he is Sadhana Catuṣṭaya Saṃpatti.  This is the mental preparedness for knowledge.
• jñāna Yoga:  The final level of bhakti is self-inquiry.  This consists of vedanta sravanam manana Nidhithyasanam, consistent systematic study of vedantic scriptures for a length of time under the guidance of competent guru (sravanam).  Krishna states this in the fourth chapter.  That nirguna eeswara is not different from me, the real me.  Any doubt that obstructs this knowledge should be removed (mananam).  Internalize and assimilate vedanta that I am the higher nature (nidhithyasanam).

When the five levels are completed, there will be a transfer of emotional personality. The first four levels belong to veda poorva and the fifth level belong to Vedanta.  These five levels do not have clear cut division.  We will be following all the sadhanas, but one of them will be predominant. 

Verses 13 to 19:  Bhakti Yoga Palam:

1. Direct benefit of bhakti yoga is atma jñānam; aham brahma asmi; I am pūrṇaḥ; I am complete.
2. Removal of ignorance:  What is the connection between intellectual knowledge and emotional benefit.  Vedanta says we are complete and pūrṇaḥ.  Due to self-ignorance, we don’t realize that we are complete.  Ignorance leads to erroneous conclusion that we are incomplete.  This erroneous conclusion is at an intellectual level.  When we feel we are incomplete, we go on struggling in life and we go after other material benefits, searching for something that will make us complete.  This is kama and it is at emotional level.  When there is obstruction to kama, there is krōdha.  Fulfilment of kama leads to more kama.  Unfulfillment of kama leads to krōdha.  Fulfilled kama leads to lōbha.  Kama is caused by ignorance – that I am incomplete – apurna.  This ignorance is at the intellectual level, but the result is at emotional level – kama and krōdha.

All our transactions are at three different levels:

1. As a kartha – doer
2. As a boktha – experiencer
3. As a Pramada or witness/observer

Benefits of bhakti yoga are:

1. As a kartha, all my actions are not meant for fulfilment but done with fulfilment (poornatvam) – acceptance of the result.
2. As a boktha, my mind has fullness, love and compassion; that mind is not vulnerable to emotional disturbances, like anger, impulsive actions etc.
3. As a Pramada,  the action comes from love and compassion without expectations, the quality of actions are excellent.  The action is sound and appropriate.  As an observer the perspective of the experiencer is tranquility not subject to raga and dwesha.

To get these benefits, everyone has to go through all five stages.