There are many types of knowledge, but there is only one greatest knowledge – this is self-knowledge, the knowledge of one's eternal True Self, this is the knowledge of the unchanging ultimate reality. Your True Self was never born and will never die.
(Sai Baba – Sathya Sai Gita Chapter 1)
The main thing for which we are born into this world is to realize the greatest secret of the True "I". This secret is what most of Sathya Sai Baba's instructions were devoted to. "I" exist – is a statement that sounds perfectly clear to every person. The obvious thing is that "I Am", even if it is not always clear what "I" is. Self-existence is so obvious that it does not need proof and discussion, as it is an experience inherent in absolutely everyone. However, the simplicity and evidence that "I" exist does not make the question of what "I" is simple.
There are many types of knowledge, all of which are very important for the development of human culture. Sathya Sai Baba never denied physics, mathematics, jurisprudence, economics, or the many other sciences important for development of human society. However, there is a knowledge that is most important, and that is knowledge about the essence of one’s soul.
Who constantly strives to be free from problems and suffering, as well as to find eternal happiness? Who wants to be successful? Who wants to receive genuine answers to the most important questions of the universe and dispel their doubts? Who seeks to know the absolute truth, thinks, and meditates? To all these complex questions, the answer is simple: “I am”.
Even if you say you do not have all these desires and questions, then we can ask: who does not have questions and desires? The answer will be exactly the same: “I” do not have desires and questions.
If someone says he does not believe in the existence of "I" at all, then it is appropriate to ask: who does not believe in the existence of "I"? and again the answer is "I". You have thoughts, feelings, desires, preferences, opinions – you do things, but at the same time, most often you forget to realize or understand who this “I” is, which thinks, feels, and acts.
The true "Self" existed before the birth of the physical body and will continue to exist after one’s death. Sathya Sai Baba never denied the numerous branches of human culture, he even founded several major universities and colleges in India, which successfully taught various disciplines, allowing graduates to get good jobs and build successful careers.
Sathya Sai Baba was extremely active in public and social life, and he taught his followers the same. Of all kinds of knowledge, Sathya Sai Baba considered the knowledge of oneself to be the highest. A person who has known his soul discovers for himself the greatest cosmic secret of the essence of being. Only then all other types of knowledge and all activity, in general, acquires a sacred meaning, otherwise everything is pure vanity.
The omnipresent "I" is invisibly present in wakefulness and in sleep, in happiness and suffering, in birth and death; it existed long before the birth of your physical body and will continue its existence after the death of the body. The body is born and dies, but the "I" is eternally present in the infinite cosmos. Everything in this world is impermanent; everything changes every second, but the True Self is an eternal observer present invisibly and invariably in the center of the constant cycle of impermanence and variability.