BG Chap 13 - The three sets of 6 chapters
The first six chapters described knowledge of the jīvātmā which is attained thru niṣkāma karma yoga, and which is useful to attain knowledge of the Lord. Liberation arising from jñāna mixed with bhakti practiced by followers of niṣkāma karma yoga and the process of jñāna was briefly discussed there. In the second six chapters worship of the Lord called bhakti was taught along with a description of the Lord’s powers. Moreover, when that worship is pure worship (kevala bhakti), one attains the Lord by bringing Him under control. The worship performed by those desiring relief from distress, wealth or knowledge brings about relief from suffering, gain of wealth and knowledge and then by association with the exclusive devotees, becomes pure. That pure bhakti then allows them to attain the Lord. When the bhakti process is mixed with jñāna or yoga, it gives perception of the majestic form of the Lord and yields liberation. In the last six chapters, the universe caused by the combination of prakṛti and puruṣa, the forms of the Lord, and the essential natures of karma, bhakti and jñāna will be explained. These chapters mainly delineate jñāna mixed with bhakti, and also kevala bhakti is shown as supreme indirectly.