The Gītā should be taken as the most perfect presentation of Vedic knowledge. Vedic knowledge is received from transcendental sources, and the first words were spoken by the Lord Himself. The words spoken by the Lord are called apauruṣeya, meaning that they are different from words spoken by a person of the mundane world who is infected with four defects. A mundaner (1) is sure to commit mistakes, (2) is invariably illusioned, (3) has the tendency to cheat others and (4) is limited by imperfect senses. With these four imperfections, one cannot deliver perfect information of all-pervading knowledge. Vedic knowledge is not imparted by such defective living entities. It was imparted unto the heart of Brahmā, the first created living being, and Brahmā in his turndisseminated this knowledge to his sons and disciples, as he originally received it from the Lord.
(Bhagavad-Gita--introduction).

In the Bhagavad-gītā the Lord says, "All the Vedas are searching after Me." Lord Śrī Caitanya says that in the Vedas the subject matters are only three, namely to establish the relation of the living entities with the Personality of Godhead, perform the relative duties in devotional service and thus achieve the ultimate goal, back to Godhead. As such, vedānta-vādīs, or the followers of the Vedānta, indicate the pure devotees of the Personality of Godhead. Such vedānta-vādīs, or the bhakti-vedāntas, are impartial in distributing the transcendental knowledge of devotional service. To them no one is enemy or friend; no one is educated or uneducated. No one is especially favorable, and no one is unfavorable. The bhakti-vedāntas see that the people in general are wasting time in false sensuous things. Their business is to get the ignorant mass of people to reestablish their lost relationship with the Personality of Godhead.
(Srimad Bhagavatam----1:5:24----purport).

Lord Brahmā is the original speaker of Vedic wisdom to Nārada, and Nārada is the distributor of transcendental knowledge all over the world through his various disciples, like Vyāsadeva and others. The followers of Vedic wisdom accept the statements of Brahmājī as gospel truth, and transcendental knowledge is thus being distributed all over the world by the process of disciplic succession from time immemorial, since the beginning of the creation. Lord Brahmā is the perfect liberated living being within the material world, and any sincere student of transcendental knowledge must accept the words and statements of Brahmājī as infallible. The Vedic knowledge is infallible because it comes down directly from the Supreme Lord unto the heart of Brahmā, and since he is the most perfect living being, Brahmājī is always correct to the letter.
(Srimad Bhagavatam----2:6:34----purport).

One's energy should be utilized for one's self-interest. That is the perfection of the energy. This energy can be utilized for real self-interest if one is compassionate. A person in Kṛṣṇa consciousness, a devotee of the Lord, is always compassionate. He is not satisfied that only he himself is a devotee, but he tries to distribute the knowledge of devotional service to everyone. There are many devotees of the Lord who faced many risks in distributing the devotional service of the Lord to people in general. That should be done.
(Srimad Bhagavatam----3:21:31----purport).

Recitation of Śrīmad-Bhāgavatam is specifically meant to enlighten people about the Absolute Truth, the Supreme Personality of Godhead. Although there is no fundamental difference between impersonal Brahman, localized Paramātmā and the Supreme Person, factual immortality cannot be obtained unless and until one attains the stage of associating with the Supreme Person. Devotional service, which leads to the association of the Supreme Lord, is actual immortality. Pure devotees, out of compassion for the fallen souls, are kṛpālu, very kind to people in general; they distribute this Bhāgavata knowledge all over the world. A kindhearted devotee is called dīna-nātha, protector of the poor, ignorant mass of people. Lord Kṛṣṇa is also known as dīna-nātha or dīna-bandhu, the master or actual friend of the poor living entities, and His pure devotee also takes the same position of dīna-nātha. The dīna-nāthas, or devotees of Lord Kṛṣṇa, who preach the path of devotional service, become the favorites of the demigods.
(Srimad Bhagavatam----4:12:51----purport).

Great personalities of the material world are very eager to render welfare service to human society, but actually no one can render better service than one whodistributes the knowledge of spiritual realization in relation with the Supreme Personality of Godhead. All living entities are within the clutches of the illusory energy. Forgetting their real identity, they hover in material existence, transmigrating from one body to another in search of a peaceful life. Since these living entities have very little knowledge of self-realization, they are not getting any relief, although they are very anxious to attain peace of mind and some substantial happiness. Saintly persons like the Kumāras, Nārada, Prahlāda, Janaka, Śukadeva Gosvāmī and Kapiladeva, as well as the followers of such authorities as the Vaiṣṇava ācāryas and their servants, can render a valuable service to humanity by disseminating knowledge of the relationship between the Supreme Personality of Godhead and the living entity. Such knowledge is the perfect benediction for humanity.
(Srimad Bhagavatam----4:22:47----purport).

Thus whoever takes birth in the land of Bhārata-varṣa attains all the facilities of life. He may take advantage of all these facilities for both material and spiritual advancement and thus make his life successful. After attaining the goal of life, one may distribute his knowledge and experience all over the world for humanitarian purposes. In other words, one who takes birth in the land of Bhārata-varṣa by virtue of his past pious activities gets full facility to develop the human form of life.
(Srimad Bhagavatam----4:25:13----purport).

Taking advantage of all the facilities offered him, a human being who has taken birth in the land of Bhārata-varṣa should become a fully enlightened devotee and go back home, back to Godhead. This is the subject matter of the Kṛṣṇa consciousness movement. The inhabitants of places other than Bhārata-varṣa have facilities for material enjoyment, but they do not have the same facility to take to Kṛṣṇa consciousness. Therefore Śrī Caitanya Mahāprabhu has advised that one who has taken birth as a human being in Bhārata-varṣa must first realize himself as a part and parcel of Kṛṣṇa, and after taking to Kṛṣṇa consciousness, he must distribute this knowledge all over the world.
(Srimad Bhagavatam----4:19:5----purport).