It is necessary for the leaders of the Krsna consciousness movement to start educational institutions in different parts of the world to train children, starting at the age of five years. Thus such children will not become hippies or spoiled children of society; rather, they can all become devotees of the Lord. The face of the world will then change automatically.
Srimad Bhagavatam
 4.12.23 Purport

Child is the father of man. Take the development of the school very, very seriously. Give them the facility to become the teachers of the next generation. Do not neglect this educational program. You GBC members take it very seriously to develop that school for the children. If we lose even one Vaisnava, it is a very great loss. This gurukula is the responsibility of every GBC man, not just the zonal secretary. You all should participate in its development.
Letter quoted in Jagadisha’s book, no further reference

The important members of ISKCON should give careful attention to our Dallas school, where children are being taught Sanskrit and English to become perfect brahmanas.
Caitanya Caritamrta Adi Lila 17.103 Purport

I consider this Gurukula school to be one of our most important aspects of this movement and it should be given all serious consideration by the members. If we are able to make a whole generation of our children into fine Krsna Conscious preachers, that will be the glory of our movement and the glory of your country as well. But if we neglect somehow or other and if we lose even one Vaisnava, that is very great loss.
Letter to Stokakrsna - Los Angeles 20 June, 1972

I am very glad to hear that all of you have been such a great help to Stoka Krsna there in our Dallas Gurukula and I can understand that all of you are very sincere boys and girls and quite eligible for going back to Home, back to Godhead. Now I very much appreciate your activities for conducting our school to the highest standard of Krishna Consciousness behavior, and I consider your work the most important in the society because you are shaping the future generation of our Krishna Consciousness preachers, and this is not any small thing.
Letter to Rupa Vilasa (Robert McNaughton), Candrika (Carol McNaughton), Bhavatarini (Debbie Watt), Bhanutanya (Debra Wolin)

I am especially stressing the importance of our Dallas Gurukula for training up the next generation of Krishna Consciousness preachers. This is the most important task ahead.
Letter to Satsvarupa - Los Angeles 1 July, 1972
 

I am also happy to hear that the Gurukula project has been given help by Karandhara and others, so that cooperatively we may demonstrate the topmost example of real education in the world.
Letter to Satsvarupa - London 8 August, 1972

If you become Head Master of the Gurukula that is more important than going to South America. This is the most important post in pushing on this movement, practically, because you shall create our preachers of the future, many, many of them.
Letter to Mohanananda - Ahmedabad 11 December, 1972

Gurukula is our most important project. If the children are given a Krsna Conscious education from early childhood then there is great hope for the future of the world.
Letter to Dayananda, Nandarani - Calcutta 27 January, 1973

It is extremely assuring to me to hear that Gurukula is doing nicely. The importance of the school in Dallas cannot be overestimated, both for our ISKCON movement, and for the outsiders as well, indeed it is important for the whole world.
Letter to Dayananda - Bombay 11 April, 1974

Now I very much appreciate your activities for conducting our school to the highest standard of Krishna Consciousness behavior, and I consider your work the most important in the society because you are shaping the future generation of our Krishna Consciousness preachers, and this is not any small thing.
Letter to Son and Daughters - 20 June 1972

It is the most important preaching work, to train our children in Krishna Consciousness education of life. …I was also at Dallas school last summer and I was very much impressed with these children, how nicely they are becoming preachers and kirtana men and girls. If we can develop properly, one day they will turn the world by their preaching.
Letter to Mohanananda - 11 December 1972

You shall both go back to home, back to Godhead, by doing this…Gurukula is our most important project. If the children are given a Krsna Conscious education from early childhood then there is great hope for the future of the world.
Letter to Dayananda and Nandarani - 27 January 1973

Now I am concerned that the Gurukula experiment should come out nicely. These children are the future hope of our Society, so it is a very important matter how we are training them in Krishna consciousness from the very childhood.
Letter to Satsvarupa - New York 11 April, 1973

So make Gurukula more solidified. Up to now it is going nicely. Keep the standard intact. People are appreciating, and they will do so more and more.
Letter to Satsvarupa - New Delhi 2 November, 1973 

Please also take care of the children. They are our future hopes, and the adolescent age is the most dangerous age. It is the turning point of one's life. In this age, if you take care of the children, surely they will come out first class Krishna Conscious devotees.
Letter to: Hayagriva — London 7 November, 1969

...So Prahlada Maharaja says, kaumara acaret prajno dharman bhagavatan iha [SB 7.6.1]. "My dear friends, from the beginning of your kaumara age, as soon as you are on the age of ten years,"... Of course, he was preaching when he was five years old. Actually, education begins, that is the Indian system, from five years. Up to five years, the children are not bothered with any kind of education. They play and become free. But as soon as he is five years old, he's sent to the school. And actual education begins from tenth year. So Prahlada Maharaja says, "My dear friends, that, you try to be educated in religion, especially in the Bhagavata religion."
Srimad-Bhagavatam 7.6.1-2 -- Stockholm, September 6, 1973

This Prahlada Maharaja, he was a small boy, five years old. Somehow or other, he was enlightened in Krsna consciousness, and at the age of five years old, he was going to school and he was trying to preach this Krsna consciousness movement in the school. I'm especially reading these verses because it is university, a school for teaching to the students. So Prahlada Maharaja says that this teaching of this learning of Krsna consciousness, should begin from very childhood. Kaumaram. Kaumara means the age between ten years and fifteen years. That is called kaumara. Kaumara acaret prajno. Prajno means one who is intelligent. So from just one child is ten years old, from the age of ten years up to fifteen years, this period must be used especially for understanding Bhagavata-dharma, for understanding what is God. That is Bhagavata-dharma….

I do not wish that the Gurukula should be closed. Please work combinedly and endeavour with great determination to keep it going on nicely.
Letter to Gurukula Devotees - Mayapur 4 March, 1976

The profits from the businesses should first go to support Gurukula and balance may be given for the local Temple's maintenance.
Letter to Jayatirtha - Mayapur 22 January, 1976

It is a fact that Gurukula must be always carefully supervised, it is one of our most important projects.
Letter to Hrdayananda - 10 May 1973

I am especially stressing the importance of our Dallas Gurukula for training up the next generation of Krishna Consciousness preachers. This is the most important task ahead. I am seeing practically how wonderful the children are coming out.
Letter to Satsvarupa - 1 July 1972

Since the Krsna consciousness movement going on at the present moment is genuine, perfect and authorized and is following in the footsteps of Prthu Maharaja, anyone who cooperates with this movement or accepts its principles will get the same result as the workers who are actively propagating Krsna consciousness.
Srimad-Bhagavatam 4.21.27 Purport