In the previous section, Krishna revealed His magic formula: it is possible to go beyond the network of illusion (māyām) simply by surrendering our life to Krishna alone (mām eva). (BG 7.14) 

Is everyone going to be ready to surrender to Krishna now? Unfortunately, no. Four categories of miscreant individuals (duṣkṛtino or whose intelligence and efforts are misdirected) will never do that: (1) mūḍhāḥ, or, those who are grossly foolish, spiritually lazy, and therefore oblivious of the real goal of life. (2) narādhamāḥ, or, those who are considered the lowest of mankind because they don’t value the opportunities awarded for spiritual elevation, (3) māyayāpahṛta-jñānā, or, whose knowledge is robbed by illusion because of obstinate independent-mindedness, (4) āsuraṁ bhāvam āśritāḥ, or those who have taken shelter of atheistic nature, and therefore endeavoring very hard to get God out of the picture in every step of their life. (BG 7.15)

On the other hand, four kinds of pious individuals (su-kṛtino) do surrender to Krishna and engage in His devotional service (bhajante). They are (1) ārto, or, a distressed person, (2) jijñāsur, or, one who is inquisitive, (3) arthārthī, or, one who is after wealth, and (4) jñānī, or, one who is in the pursuit of knowledge of the Absolute Truth by philosophical or mental speculation. (BG 7.16)

Out of these, one who is in the pursuit of knowledge (jñānī) and at the same time exclusively (eka) devoted to Krishna (bhaktir) stands out (viśiṣyate). Krishna is very dear to such a person (’tyartham ahaṁ) and he/she is also dear to Krishna (sa ca mama priyaḥ). (BG 7.17) Although Krishna considers all the surrendered souls as magnanimous, He considers a devotionally surrendered knowledgeable soul (jñānī) just like His own Self. Krishna reassures that because of being situated on the platform of devotional service (āsthitaḥ sa hi yuktātmā), such a soul is sure to attain Krishna, the highest and most perfect goal (mām evānuttamāṁ gatim). (BG 7.18)

Is every one who is in the pursuit of knowledge (or, jñānī) going to come to the stage of exclusive devotion to Krishna? And, how long is it going to take? Krishna’s verdict is that it is very rare (su-durlabhaḥ) for even one who is in full knowledge (jñānavān) to come to the stage of devotion, what to speak of a jñānī who is pursuing knowledge by the process of mental speculation. In fact, it takes many many births (bahūnāṁ janmanām ante) for a jñānavān to come to the conclusion that Krishna is the summum bonum of everything (vāsudevaḥ sarvam iti), and therefore he/she should engage in Krishna’s exclusive devotional service (prapadyate). (BG 7.19) Note that here, Krishna uses the same word, prapadyate that He used in giving us the magic formula for escaping illusion in BG 7.14. In other words, it is going to take an inordinate amount of time for a jñānī to escape illusion.

The bottom line is that we should not be a mental speculator (BG 7.19) but an ardent listener (BG 7.1) and we should hear in an authorized disciplic succession.