The Highest Endeavor:

You may control a mad elephant;
You may shut the mouth of the bear and the tiger;
Ride the lion and play with the cobra;
By alchemy you may earn your livelihood;
You may wander through the universe incognito;
Make vassals of the gods; Be ever youthful;
You may walk on water and live in fire;
But control of the mind is better and more difficult.
-Thayumanavar the great South Indian sage.

I Am the Self in the Heart of All Creatures

Arjuna:
O Krishna, O Origin of beings, O Lord of all creatures, O God of gods, O Sustainer of the world! verily Thou alone knowest Thyself by Thyself. Therefore, please tell me exhaustively of Thy divine powers and qualities by which Thine Omnipresence sustaineth the cosmos. O great Yogi! how shall I always meditate in order to know Thee truly?...

Krishna:
...I am the Self in the heart of all creatures: I am their Origin, Existence, and Finality.
-Bhagavad Gita X:15-17,20


"What one finds if one studies the various forms of mysticism is that the doctrines of the mystics are much less diverse than are religious doctrines. My interpretation of this is that mysticism is concerned with very fundamental laws... I consider mysticism to be something universal like scienece [and that] religions are based on the facts of science. Thus mysticism is a kind of universal foundation for the diverse and different religions. I should mention here that I'm not talking entirely about Eastern mysticism, because there is Western mysticism as well: e.g., Christian mysticism, Islamic mysticism (Sufism), and Jewish mysticism. These all say rather similar things.
"...Mystical experience by self-development through meditation, etc., is not only the key to one's own development but also the key... to putting this attempt to synthesize science and religion on a solid foundation... If we follow this path of a system of science with religion (using meditation as an observational tool), what we are doing is using our own nervous systems as instruments to observe the domains in which God works. Ordinary scientific instruments like telescopes, galvanometers, and particle detectors are not going to be good in this context because they are designed to function in the material domain. Our nervous systems, on the other hand, are designed to allow us to interact not only with the material level of existence but also with the spiritual levels. ...All the different levels are open to exploration if we develop our nervous systems so thet they tune in. One can imagine that this would be a part of the scientific training of the future."
-Nobel physicist Brian Josephson of Cambridge University, 1985