All material activities involve actions and reactions in the three modes of material nature. They are meant for fruitive results, which cause bondage in the material world. The Vedas deal mostly with fruitive activities to gradually elevate the general public from the field of sense gratification to a position on the transcendental plane. Arjuna, as a student and friend of Lord Kṛṣṇa, is advised to raise himself to the transcendental position of Vedānta philosophy where, in the beginning, there is brahma-jijñāsā, or questions on the supreme transcendence. All the living entities who are in the material world are struggling very hard for existence. For them the Lord, after creation of the material world, gave the Vedic wisdom advising how to live and get rid of the material entanglement. When the activities for sense gratification, namely the karma-kāṇḍa chapter, are finished, then the chance for spiritual realization is offered in the form of the Upaniṣads, which are part of different Vedas, as the Bhagavad-gītā is a part of the fifth Veda, namely the Mahābhārata.
(Bhagavad-Gita---2:45---purport).

By development of Kṛṣṇa consciousness one can know that everything has its use in the service of the Lord. Those who are without knowledge of Kṛṣṇa consciousness artificially try to avoid material objects, and as a result, although they desire liberation from material bondage, they do not attain to the perfect stage of renunciation. Their so-called renunciation is called phalgu, or less important. On the other hand, a person in Kṛṣṇa consciousness knows how to use everything in the service of the Lord; therefore he does not become a victim of material consciousness. For example, for an impersonalist, the Lord, or the Absolute, being impersonal, cannot eat. Whereas an impersonalist tries to avoid good eatables, a devotee knows that Kṛṣṇa is the supreme enjoyer and that He eats all that is offered to Him in devotion. So, after offering good eatables to the Lord, the devotee takes the remnants, called prasādam.
(Bhagavad-Gita---2:63---purport).

The injunction of the Supreme Personality of Godhead, Kṛṣṇa, is the essence of all Vedic wisdom and therefore is eternally true without exception. As the Vedas are eternal, so this truth of Kṛṣṇa consciousness is also eternal. One should have firm faith in this injunction, without envying the Lord. There are many philosophers who write comments on the Bhagavad-gītā but have no faith in Kṛṣṇa. They will never be liberated from the bondage of fruitive action. But an ordinary man with firm faith in the eternal injunctions of the Lord, even though unable to execute such orders, becomes liberated from the bondage of the law of karma. In the beginning of Kṛṣṇa consciousness, one may not fully discharge the injunctions of the Lord, but because one is not resentful of this principle and works sincerely without consideration of defeat and hopelessness, he will surely be promoted to the stage of pure Kṛṣṇa consciousness.
(Bhagavad-Gita----3:31--purport).

When we speak of transcendental knowledge, we do so in terms of spiritual understanding. As such, there is nothing so sublime and pure as transcendental knowledge. Ignorance is the cause of our bondage, and knowledge is the cause of our liberation. This knowledge is the mature fruit of devotional service, and when one is situated in transcendental knowledge, he need not search for peace elsewhere, for he enjoys peace within himself. In other words, this knowledge and peace culminate in Kṛṣṇa consciousness. That is the last word in the Bhagavad-gītā.
(Bhagavad-Gita---4:38---purport).