The plain truth is that the Supreme Godhead the Father, the nature material is the mother and all living entities are so many children of almighty father Godhead, and the mother nature. The whole arrangement is just a family unit, and we should wonder as to why there is so much anomaly in this great universal family unit.
Letter to Secretary of Sri Gita Mandir Trust, 1 September, 1949
If he likes he can go back to Godhead, "yanti mad yajino 'pi mam,'' [BG 9.25] and stop this transmigration process. Then he comes again perfect in Krishna consciousness. We are trying to bring the human society to this stage of life. In human life even in the lower stage of modes of nature, he can come to the higher stage. That is our movement. In the animal form there is no chance, only in the human form. Unfortunately the modern mode of education is to kill the chance. In animal stage of life it is very dangerous.
Letter to Svarupa Damodara das, 31 August, 1975
According to quality and according to work, the social order is divided into four. The most intelligent class of men are called the brahmanas, and the next intelligent class of men, namely the politicians, or one who wants to take part in administration, they are called ksatriyas. And the next intelligent class of men, those who are busy in production - because we want food - so the productive class of men is called vaisya, mercantile. And the laborer class of men, namely one who is neither intelligent nor administrator nor trader, but wants to live at the shelter of somebody, master, they are called sudras. The brahmanas, the ksatriyas, and the vaisya, they would never accept subordination, service, under anyone. But the sudras, as it is stated in the Bhagavad-gita: paricaryatmakam karyam sudra-karma svabhava-jam [Bg. 18.44]. By nature, a sudra wants to take shelter of somebody else and live. So at the present moment, the Kali-yuga, the sastra says, almost everyone is a sudras because nobody can live independently.
Lecture on Srimad-Bhagavatam 5.5.1, London, 30 August, 1971
Meat-eating is sinful. Why? What is the sin there? Illicit sex, what is the wrong there? Intoxication, what is wrong there? They do not find any immorality. So this standard of morality, there cannot be fixed up if one is not God conscious. Standard of morality, standard of goodness, cannot be. That is the decision of the Srimad-Bhagavatam. Harav abhaktasya kuto mahad-gunah. Lack of Krsna consciousness. They think that animal has no soul. They do not accept this morality that animal cannot be killed, it is sinful, it is immoral. They have created their own theory. So without being standardized by Krsna consciousness, or God consciousness, you cannot find the standard platform of morality, honesty.
Lecture on Bhagavad-gita 2.26-27, London, August 29, 1973
K.C. gives us the opportunity of rendering service to Krishna, and this service attitude only can replace us on our original position. Please therefore, continue to chant faithfully, and Krishna will reveal Himself, by His Causeless Mercy, and you will know everything automatically.
Letter to Jananivasa, 27 August, 1967
Those who have surrendered to the material nature, he has to suffer. There is no way out. You have accepted this body. You must suffer. Klesada asa dehah. This material body means suffering. So they do not know this. They are making so many arrangements and plans how to become happy, how to become peaceful without any miserable condition, but the rascals, they do not know that so long you have got this material body - either a king's body or an ant's body - you must have to suffer.
Lecture on Bhagavad-gita 2.25, London, 28 August, 1973
I am sorry to learn that you are not well. Pray to Krishna and chant Hare Krishna. The body is a temple of disease, janma mrtyu jara vyadhi [BG 13.9]. Disease is our inevitable companion. We still have to execute our duty of Krishna consciousness as far as possible and Krishna will help us.
Letter to Dinesh Candra Sarkar, 26 August, 1976
Nobody kills anybody, neither anybody is killed by others. This is one thing. Again, in a different way, Krsna says, na jayate: the living entity never takes birth. The birth is of the body or the death is of the body. Living entity, the spiritual spark, then that being Krsna's part and parcel, as Krsna does not take birth, does not die... Ajo 'pi sann avyayatma. You'll find in the Fourth Chapter. Ajo 'pi. Krsna is aja. Aja means who never takes birth. Similarly, we being part and parcel of Krsna, we also never take birth. The birth and death is of this body, and we are so absorbed in the bodily concept of life that when there is birth or death of the body we feel the pains and pleasures.
Lecture on Bhagavad-gita 2.19, London, August 25, 1973
The more we struggle for advancing our Krishna Consciousness movement, the more we become advanced on the path. Really, devotional service means that we have to employ our energies for the purpose of Krishna Consciousness, and it does not matter what is the volume of such energy, because different persons have got different type of energies, but the best means is that one has to apply his energy as far as possible, that is the secret of success in Krishna Consciousness.
Letter to Aniruddha, 24 August, 1968
There are three stages: jagarti, svapna, susupti. Anyone has got this experience. One stage is that you are awakened, another stage is sleeping, and another stage is unconscious. Jagarti, svapna and susupti, the Sanskrit name. Jagarti, when you are awakened, our consciousness is very acute, very strong. In sleeping stage, there is consciousness, but it is not so active. And unconscious stage means consciousness is some way or other subdued, not working. Three stages. So death means that unconsciousness for a long period. That is death. Because the soul is eternal. It will be explained. There is no birth and death. So when this body is annihilated, so the soul remains unconscious for a period, seven months for a human being. Seven months unconscious stage within the womb of the mother. After seven months, the consciousness revives. Just like if you have got an experience under chloroform, unconsciousness. The surgical operation takes place, you do not understand, you do not perceive pains and pleasure, but you remains for a certain hours unconscious. Then, gradually, dream comes. Just, from unconsciousness the dream comes. And from dream, you are awakened. As you go down from awakening stage to dream, dream to unconsciousness, similarly, you come up also, from unconsciousness to dream, from dream to awakening conscious stage.
Lecture on Bhagavad-gita 2.17, London, 23 August, 1973