Delusion Of Senses (18.36-18.54)
Now Kṛṣṇa talks about how we respond as a result of root patterns based on the influence of guṇas (attributes).
Kṛṣṇa says that spiritual practice, that is the state of satva, is difficult in the beginning, and it is like poison; but, it becomes life-giving nectar in the end. Sensual pleasures born out of rajas, seem like nectar in the beginning but become poisonous. In the tamasic state, one is deluded as if in sleep, laziness and illusion. Every human is in one state or another. No one can escape the effect of guṇas, the attributes of Nature.
Sreyān svadharmo viguṇaḥ paradharmāt svanuṣṭhitāt (18.47)—says Śrī Kṛṣṇa. It is better to do one's assigned work imperfectly than do another's work perfectly. It is possible that one can perform elements of another's work well.
Work Always Under My Protection (18.54-18.58)
Kṛṣṇa explains how devotion is reached and how He protects the devotee. When one is in Kṛṣṇa consciousness, the devotee, even if he is engaged in worldly activities, is protected by the grace and compassion of Kṛṣṇa. Without any difficulty such a devotee reaches the ultimate reality.
The person who surrenders gets the best experience in both inner and outer worlds. We simply need to get out and He will get in. Just get out and let Him get in. When you surrender the instinct to survive and possess, Kṛṣṇa will protect you. His energy takes care. Kṛṣṇa says you will perish, if you follow your mind and senses instead of listening to Him.
Devotion and Knowledge are not Separate
Kṛṣṇa says that 'having known Me in essence–māṁ tattvato jñātvā, My devotee merges in Me, viśate tad-anantaram (18.55)' and refers to this as devotion. Bhakti (devotion) and jñāna (knowledge) are not separate. Where there is devotion, there is knowledge and where there is true knowledge, there is devotion.
Every word of Gītā, every word of Kṛṣṇa, is energy. The purpose of Gītā is to enrich you to complete with your root patterns and drop the ego! All you need to do is understand one verse of Gītā, one statement of Kṛṣṇa, in its entirety. That is the knowledge that you need to imbibe and experience. This is what the 'knowing, tattvato jñātvā' that Kṛṣṇa refers to. Once you 'know' this energy, you become Kṛṣṇa. You are not only devoted to Kṛṣṇa, you become Kṛṣṇa.