We have to give up all other material desires, simply stick to Kṛṣṇa to serve Him, always ready to serve Him. Ānukūlyena kṛṣṇānu-śīlanam (CC Madhya 19.167). Just like Arjuna. He was ready to serve Kṛṣṇa. Similarly, everyone should be ready to serve Kṛṣṇa. That is the perfection of life.
So one has to execute this process of devotional service, as Kṛṣṇa said, mad-āśraya: "Take shelter of Me or My devotee." Now, at the present moment, in the teachings of Bhagavad-gītā Kṛṣṇa is personally instructing, so let us take shelter of His personal instruction and make our life successful. And not only he becomes a devotee, but a pure devotee understands Kṛṣṇa as it is said here, asaṁśayaṁ samagram, not partially but fully. It is, of course, not possible to understand Kṛṣṇa fully. Still, almost fully a devotee can understand Kṛṣṇa. That is also confirmed in the last paragraph, last chapter:
- bhaktyā mām abhijānāti
- yāvān yaś cāsmi tattvataḥ
- tato māṁ tattvato jñātvā
- viśate tad-anantaram
- (BG 18.55)
So if we want to go back to home, back to Godhead, then we must increase our attachment for Kṛṣṇa, and by that process we can understand Kṛṣṇa, what He is. Bhaktyā mām abhijānāti (BG 18.55). Then our door to go back to home, back to Godhead, is clear. The conclusion is, therefore, that we should take to the bhakti process as it is enunciated in authoritative śāstra, by Kṛṣṇa, by the ācāryas. Sarva-dharmān parityajya mām ekaṁ śaraṇaṁ vraja (BG 18.66). That is the way, only, for our perfection of life.