For example, a brāhmaṇa who is born out of the head of the Lord has as his business to preach the transcendental Vedic sounds, or śabda-brahman. Because the brāhmaṇa is the head, he has to preach the transcendental sound, and he also has to eat on behalf of the Supreme Lord. According to Vedic injunctions, when a brāhmaṇa eats it is to be understood that the Personality of Godhead is eating through him. It is not, however, that the brāhmaṇa should simply eat on behalf of the Lord and not preach the message of the Bhagavad-gītā to the world. Actually, one who preaches the message of the Gītā is very dear to Kṛṣṇa, as is confirmed in the Gītā itself. Such a preacher is factually a brāhmaṇa and thus by feeding him one feeds the Supreme Lord directly.
Similarly, the kṣatriya has to protect people from the onslaughts of māyā. That is his duty. For example, as soon as Mahārāj Parīkṣit saw that a black man was attempting to kill a cow, he immediately took his sword, wanting to kill the black man, whose name was Kali.* That is a kṣatriya's duty. Violence is required in order to give protection. In the Bhagavad-gītā, Lord Kṛṣṇa directly gave His order to Arjuna to commit violence on the battlefield of Kurukṣetra, just to give protection to the people in general.
- Not to be confused with Kālī, the demigoddess who is the devastating feature of material nature. The latter is actually pronounced kāh-lee, whereas the Kali under discussion here (as in the age of kali) is pronounced kuh-ly.
The vaiśyas are meant for producing agricultural products, trading them and distributing them. And the working class, or śūdras, are those who haven't the intelligence of the brāhmaṇas or the kṣatriyas or the vaiśyas, and therefore they are meant to help these higher classes by bodily labor. In this way, there is full cooperation and spiritual advancement amongst all the different orders of society. And when there is no such cooperation, the members of society will fall down. That is the present position in the kali-yuga, this age of quarrel. Nobody is doing his duty, and everyone is simply puffed-up by calling himself a brāhmaṇa (intellectual) or a kṣatriya (soldier or statesman). But actually, such people are without status. They are out of touch with the Supreme Personality of Godhead because they are not Kṛṣṇa conscious. Therefore the Kṛṣṇa consciousness movement is intended to set the whole of human society in proper condition so that everyone will be happy and take profit from developing Kṛṣṇa consciousness.
Lord Śrī Kṛṣṇa instructed Uddhava that by following the injunctions of the social and spiritual orders of human society one can satisfy the Supreme Personality of Godhead, and as a result of such satisfaction the whole society gets all the necessities of life amply and without difficulty. This is because, after all, the Supreme Personality of Godhead maintains all other living entities. If the whole society performs its respective duties and remains in Kṛṣṇa consciousness, there is no doubt that all of its members will live very peacefully and happily. Without wanting the necessities of life, the whole world will be turned into Vaikuṇṭha, a spiritual abode. Even without being transferred to the kingdom of God, by following the injunctions of the Śrīmad-Bhāgavatam and prosecuting the duties of Kṛṣṇa consciousness, all human society will be happy in all respects.
There is a similar statement by Śrī Kṛṣṇa Himself to Uddhava in the Eleventh Canto of Śrīmad-Bhāgavatam, 5th Chapter, 2nd verse. The Lord says there, "My dear Uddhava, all persons are engaged in activities, whether those indicated in the revealed scriptures or ordinary worldly activities. If by the result of either of such activities they worship Me in Kṛṣṇa consciousness, then automatically they become very happy within this world as well as in the next. Of this there is no doubt." We can conclude from this statement by Kṛṣṇa that activities in Kṛṣṇa consciousness will give everyone all perfection in their desires.