There are many examples given of how we are to utilize those things which are set aside for us by the Lord. This is also explained in Bhagavad-gītā. In the beginning, Arjuna decided that he should not fight in the Battle of Kurukṣetra. This was his own decision. Arjuna told the Lord that it was not possible for him to enjoy the kingdom after killing his own kinsmen. This decision was based on the body because he was thinking that the body was himself and that his bodily relations or expansions were his brothers, nephews, brothers-in-law, grandfathers and so on. Therefore he wanted to satisfy his bodily demands. Bhagavad-gītā was spoken by the Lord just to change this view, and at the end Arjuna decides to fight under the directions of the Lord when he says, kariṣye vacanaṁ tava (BG 18.73): "I shall act according to Your word."
In this world men are not meant for quarreling like cats and dogs. Men must be intelligent to realize the importance of human life and refuse to act like ordinary animals. A human being should realize the aim of his life, and this direction is given in all Vedic literatures, and the essence is given in Bhagavad-gītā. Vedic literature is meant for human beings, not for animals. Animals can kill other living animals, and there is no question of sin on their part, but if a man kills an animal for the satisfaction of his uncontrolled taste, he must be responsible for breaking the laws of nature. In the Bhagavad-gītā it is clearly explained that there are three kinds of activities according to the different modes of nature: the activities of goodness, of passion and of ignorance. Similarly, there are three kinds of eatables also: eatables in goodness, passion and ignorance. All of this is clearly described, and if we properly utilize the instructions of Bhagavad-gītā, then our whole life will become purified, and ultimately we will be able to reach the destination which is beyond this material sky. (BG 15.6)
That destination is called the sanātana sky, the eternal, spiritual sky. In this material world we find that everything is temporary. It comes into being, stays for some time, produces some by-products, dwindles and then vanishes. That is the law of the material world, whether we use as an example this body, or a piece of fruit or anything. But beyond this temporary world there is another world of which we have information. That world consists of another nature, which is sanātana, eternal. Jīva is also described as sanātana, eternal, and the Lord is also described as sanātana in the Eleventh Chapter. We have an intimate relationship with the Lord, and because we are all qualitatively one—the sanātana-dhāma, or sky, the sanātana Supreme Personality and the sanātana living entities—the whole purpose of Bhagavad-gītā is to revive our sanātana occupation, or sanātana-dharma, which is the eternal occupation of the living entity. We are temporarily engaged in different activities, but all of these activities can be purified when we give up all these temporary activities and take up the activities which are prescribed by the Supreme Lord. That is called our pure life.
The Supreme Lord and His transcendental abode are both sanātana, as are the living entities, and the combined association of the Supreme Lord and the living entities in the sanātana abode is the perfection of human life. The Lord is very kind to the living entities because they are His sons. Lord Kṛṣṇa declares in Bhagavad-gītā, sarva-yoniṣu. .. ahaṁ bīja-pradaḥ pitā: "I am the father of all." Of course there are all types of living entities according to their various karmas, but here the Lord claims that He is the father of all of them. Therefore the Lord descends to reclaim all of these fallen, conditioned souls, to call them back to the sanātana eternal sky so that the sanātana living entities may regain their eternal sanātana positions in eternal association with the Lord. The Lord comes Himself in different incarnations, or He sends His confidential servants as sons or His associates or ācāryas to reclaim the conditioned souls.