What is the work that needs to be done by people belonging to different castes ?

The answer to this question is given by lord krishna says in chapter 18..
                            
                       brahmana-kshatriya-visam, shudranam ca parantapa
                  karmani pravibhaktani, svabhava-prabhavair gunaih
                                                                       ...B.G.CHAPTER 18 SLOKA 41   
English translation-  “The duties of Brahmin, Kshatriya, Vaishya, as also of Shudr are determined by properties that are born out of their nature.’’


Lord krishna once again clearly states that the innate property of a being or object is a measurea yardstick. So the division of mankind into four varn is only a division of the one and same action into four stages according to the motivating properties. In Krishn’s words, action is the mode of attaining to the one, inexpressible God. The conduct that takes one to God is worship, which commences in faith in the desired end. So meditation on the Supreme Being is the one true action that Krishn has-divided into four steps in his system of varn. Now, how are we to know to which property and stage we belong? This is what Krishn turns to in the following verses.
              samo damas tapah shaucam ksantir arjavam eva ca
             jnanam vijnanam astikyam brahma-karma svabhava-jam
                                                      ...B.G.CHAPTER 18 SLOKA 42
English translation- “Self-restraint, subduing of the senses, innocence, continence, mercy, uprightness, piety, true knowledge, and direct perception of divinity are the Brahmins province-born our of his nature.


It might be said, therefore, that the seeker is a Brahmin when all these merits are present in him and the commenced action is an integral part of his nature.

             sauryam tejo dhrtir daksyam yuddhe capy apalayanam
            danam ishvara-bhavas ca kshatram karma svabhava-jam
                                                         ...B.G.CHAPTER 18 SLOKA 43


English translation- “Valour, majesty, dexterity, unwillingness to retreat in battle, charity, and sovereignty are the natural province of a Kshatriya.”

               krsi-go-raksya-vanijyam vaishya-karma svabhava-jam
              paricaryatmakam karma shudrasyapi svabhava-jam
                                                         ...B.G.CHAPTER 18 SLOKA 44
English translation- “Farming, protection of cows (the senses) and commerce are the natural province of a Vaishya, whereas rendering service is the natural calling of a Shudr.’’


Agriculture, rearing of cattle, and commerce are duties in keeping with the nature of a Vaishya.  In the ancient Vedic text, the word “go” (cow) was used to refer to the senses. So protection of “cows” means care of the senses. The senses are protected by discernment, non-attachment, restraint, and steadfastness. They
are, on the other hand, riven and rendered feeble by lust, wrath, avarice, and attachment. Spiritual acquisition is the only true wealth.This is our one true asset and once it has been earned, it stays on with us forever. Gradual amassing of this wealth in the course of our struggle with the world of matter or nature is trade. The
acquisition of knowledge, which is the most precious of all riches, is commerce. And what is farming? The body is like a piece of earth. The seeds which are sown in it sprout in the form of sanskarthe merits of action: the force that is built up by all the actions in previous lives. Arjun is told that the seed (the initial impulse) of
selfless action is never destroyed. Vaishya is the third step of the ordained action- of contemplation of the Supreme Being; and preservation of the seeds of divine meditation that are sown in this patch of earth-the body, while at the same time opposing hostile impulses, is agriculture.To protect the senses
thus, to store spiritual wealth amidst the skirmishes of nature, and to always strengthen contemplation of the ultimate essence are the province of Vaishya. According to Krishn, the omnipresent God is the final outcome
of yagya. The devout souls who partake of this fruit are emancipated from all sins and it is the seeds of this action that are sown by the meditative process. To protect this germ is true husbandry. In Vedic writings food means the Supreme Spirit. God is the only real sustenance-the food. The Soul is fully placated at the completion of the exercise of contemplation and never again knows any craving. Once the exercise has been brought to successful conclusion, the Soul is freed from the cycle of birth and death. To go ahead sowing
the seeds of this food is true husbandry.


To serve those who have attained to a higher spiritual status, revered men of accomplishment, is the duty of Shudr. Rather than meaning “base’’, Shudr means “one with deficient knowledge.” It is the seeker at the lowest stage who is a Shudr. It is but proper that this initiate worshipper should begin his quest with rendering
service. Service to men of accomplishment will in the course of time generate nobler impulses in him and he will thus gradually move up to the higher Vaishya, Kshatriya, and Brahmin stages. And ultimately he will go beyond varn (properties of nature) and become one with God. Character is a dynamic entity. There is changein an individual’s varn along with changes in his character. So, in fact, varn are the four-excellent, good, medium, and low-stages: the four steps, low and high, which seekers who tread the path of action have to climb. This is so because the action in question is only one-the ordained action. The only way to final attainment according to Krishn is that the worshipper should begin his journey in keeping with the attributes of his own nature.
                  sve sve karmany abhiratah, samsiddhim labhate narah
                  sva-karma-niratah siddhim, yatha vindati tac chrnu
                                                     ...B.G.CHAPTER 18 SLOKA 45
English translation- “Commitment to his own inborn duty brings man to the ultimate accomplishment and you should listen to me on how a man achieves perfection through dedication to his innate calling.’’


By following his qualities of work, every man can become perfect. Now please hear from Me how this can be done.

                   yatah pravrttir bhutanam, yena sarvam idam tatam

                  sva-karmana tam abhyarcya,siddhim vindati manavah
                                                           ...B.G.CHAPTER 18 SLOKA 46
English translation- “By adoration of that God, who has created all beings and who pervades the whole universe, through the undertaking of his natural calling, man attains to final accomplishment.’’


The seeker achieves final consummation through performance of his native duties. It is, therefore, essential that he should constantly keep his mind fixed on God, adore him, and proceed on his way step by step. Instead of making any gain, a junior student even loses whatever he has if he sits in a senior class. So the law is that one should climb step by step.Krishn says that even a partially enlightened man ought to begin from the same point: from self surrender to God.

                sreyan sva-dharmo vigunah, para-dharmat sv-anusthitat
                svabhava-niyatam karma, kurvan napnoti kilbisam 
                                                      ...B.G.CHAPTER 18 SLOKA 47
English translation- “Even though unmeritorious, one’s own native calling is superior to the office of others, for a man carrying out his natural obligation does not bring sin upon himself.”


Although inferior, one’s own obligation is better than even the well performed duties of others. A man absorbed in performing a task that is determined by his own nature does not incur sin in so far as he is not subjected to the endless cycle of “entrances” and “exits”-of birth and death. It is quite often that worshipers begin to feel disenchanted with the service they are rendering-. They look at the more accomplished seekers who are absorbed in meditation and grow envious of the honor that is accorded them because of their merits. So novices at once fall to imitating. According to Krishna, however, imitation or envy can be of no avail. The final accomplishment is only by dedication to one’s own native calling, not by its abandonment.

This stanza completes the question that what is the duty the people belonging to different castes...OM TATSAT..!!

         

                                                                                         

      

What does Gita say about caste system prevalent in the hindu society?

In Bhagabat Gita lord krishna first brings the topic of caste in chapter 2 when he says

              sva-dharmam api caveksya na vikampitum arhasi
             dharmyad dhi yuddhac chreyo ’nyat kshatriyasya na vidyate
                                                        ...B.G.CHAPTER 2 SLOKA 31    

English translation-  “In view of your own dharm, too, it is unworthy of you to fear, for there is nothing more propitious for a Kshatriya than a righteous war.’’


It has been repeatedly said by lord krishna that “the Self (Atma) is immutable,” that “the Self is eternal,” and that “the Self is the only real dharm.” Now what is this dharm of the Self (swadharm)? The Self is the only dharm, although the capacity to engage in this dharm varies from individual to individual. This ability arising from one’s disposition has been named swadharm or the inherent dharm.

To make matters clear around this subject of caste let us go to chapter 4 of Bhagabat Gita where lord krishna says..
                         catur-varnyam maya srstam guna-karma-vibhagasah
                 tasya kartaram api mam viddhy akartaram avyayam 
                                                  ...B.G.CHAPTER 4 SLOKA 13    

English translation- “Although I have created the four classes (varn )-Brahmin, Kshatriya, Vaishya and Shudr-according to innate properties and actions, know me the immutable as a nondoer.’’

In this sloka lord krishna clearly says that I have created the four castes (or classes) i.e. Brahman, Khatriya, Baishya and Shudra. Does this mean that the great lord has divided men into four rigid categories determined by birth? The truth is rather that he has divided actions into four classes on the basis of inherent properties. All the same, as he tells Arjun, he-the imperishable God-is a non-agent and should be known as such. The innate property (gun) of a being or of a thing is a measure, a yardstick.

In the starting stage of any yogi when he begins the journey to unify with paramatman the dominant property is that of ignorance or darkness (tamas), it will result in an irresistible inclination to laziness, excessive sleep, wantonness, aversion to work, and compulsive addiction to evil in spite of the realization that it is evil. At this stage the yogi is shudra. (This is not determined by birth. Even if the yogi is born into a family of brahmin he will still be shudra when he starts the journey to unification).

 Later with the service to wise men which is the work that should be done by shudras he cultivates and develops there is the growing sway of the quality of rajas, and a partial awakening of the property of good and moral virtue (sattwa) as well, because of which the worshipper’s ability is elevated to the Vaishya level. Then the same worshipper begins spontaneously to imbibe qualities such as control of the senses and to accumulate other virtuous impulses.


Proceeding further on the path of action, he is endowed with the wealth of righteousness. The property of
rajas now grows faint and tamas is dormant. At this stage of development the worshipper steps on to the Kshatriya level. Prowess, the ability to be immersed in action, unwillingness to retreat, mastery over feelings, the capacity to carve his way through the three properties of nature-are now the inherent features of the
worshipper’s disposition.



With yet further refinement of action, sattwa makes its approach, at which there is the evolution of virtues
such as control of the mind and senses, concentration, innocence, contemplation and abstract meditation, and faith as well the capacity to hear the voice of God-all qualities that provide access to Him. With the emergence of these qualities the worshipper comes to belong to the Brahmin class.

This, however, is the lowest stage of worship at this level. When ultimately the worshipper is united with God, at that point-the highest point-he is neither a Brahmin, nor a Kshatriya, nor a Vaishya, nor a Shudr. So in 2nd chapter lord krishna advices arjun..
                 trai-gunya-visaya veda nistrai-gunyo bhavarjuna
            nirdvandvo nitya-sattva-stho niryoga-ksema atmavan
                                                                      ...B.G.CHAPTER 2 SLOKA 45    

English translation- “Since all the Ved, O Arjun, only illumine the three properties, you should rise above them, be free from the contradictions of happiness and sorrow, rest on that which is constant, and be unconcerned with getting what you do not have as well as with protecting what you have, in order to dedicate yourself to the Self within.”


Krishna tells arjun The Ved only illumine the three properties of nature; they know nothing of what is beyond them. So Arjun should go beyond the sphere of action laid down by the Ved. How to do this? Krishnadvises Arjun to liberate himself from the conflicts of joy and sorrow,concentrate on the one changeless reality, and desire neither the unobtained nor the obtained; so that he may devote himself singlemindedly to the indwelling Self. This is how he can rise above the Ved. But is there any precedence of anyone going beyond them?
Krishn says that as a man transcends the Ved, even so he comes face to face with the Supreme Spirit, and that the man who is aware of him is a true Vipr, a Brahmin. Arjuna is a khatriya ..but lord krishna says him to become brahman. So it is clear that the caste or class is not determined by birth but are determined by the state of gunas. 


Now the question arises what is the work that needs to be done by people belonging to different castes ?