Do not go about worshipping deities and religious institutions as the source of the subtle truth. To do so is to place intermediaries between yourself and the divine, and to make of yourself a beggar who looks for a treasure that is hidden inside his own breast.
- Lao Tzu, from the Hua Hu Ching

The effulgent Self, who is beyond thought, shines in the greatest, shines in the smallest, shines in the farthest, shines in the nearest, shines in the secret chamber of the heart.
Mundaka Upanishad

Not many realize that the development of the heart means, first of all, the broadening of the consciousness. Verily, the heart is the throne of the consciousness, but not sentimentality, this surrogate of benevolence.
From the Teachings of Agni Yoga

The Lord of Love, omnipresent, dwelling in the heart of every living creature, all mercy, turns every face to himself. He is the supreme Lord, who through his grace moves us to seek him in our own hearts. He is the light that shines forever. He is the inner Self of all, hidden like a little flame in the heart. Only by the stilled mind can he be known. Those who realize him become immortal.
Shvetashvatara Upanishad

The whole work of turning the light around uses the method of reversal. The beauties of the highest heavens and the marvels of the most sublime realms are all within the heart: this is where the perfectly open and aware spirit concentrates. Confucians call it the open center, Buddhists call it the pedestal of awareness, Taoists call it the ancestral earth, the yellow court, the mysterious pass, the primal opening.
The Secret of the Golden Flower: The Classic Chinese Book of Life

The personality becomes a reflection of the smile of cosmic action when it considers itself as an inseparable part of the existing, manifested Cosmos.
From the Teachings of Agni Yoga

Surya Vidya—thus was the Teaching of the Heart sometimes called. In this definition was indicated the fieriness, the sunlike quality, the centrality of the heart. Verily, anyone who wishes to cognize the heart cannot approach it as only a part of the organism. First of all, one should recognize the centrifugal aspect of the heart and study outward from it, not inward toward it. The solar plexus is the antechamber of the temple of the heart. The Kundalini is the laboratory of the heart. The brain and all the centers are the estates of the heart, because nothing can exist without the heart. Even the brain can be supplemented to a certain degree. Even the Kundalini can be somewhat nourished by a manifestation of electricity, and the solar plexus can be strengthened by blue light. But the heart stands as the temple of humanity. One cannot conceive of the unity of humanity by way of the brain or the Kundalini, but the radiance of the heart can bring together the most seemingly varied organisms, even across remote distances. This experiment, of the unification of hearts across distance, awaits its workers.
From the Teachings of Agni Yoga

The Lord of Love, not larger than the thumb, is ever enshrined in the Hearts of all.
Katha Upanishad

A hardened heart will not ascend to the Tower. It will not give strength to the subtle body. Such a stony heart will remain within the confines of Earth.
From the Teachings of Agni Yoga

The Chalice, the Anahata Chakra, or the Heart of the Subtle Body, is where the accumulations of many lives are stored, deposited there in the form of Fiery Matter. Since times immemorial, the Chalice has been a symbol of Service. The gifts of Higher Forces are gathered in the Chalice and given from the Chalice. The symbol of the Chalice has always stood for self-sacrifice. Whoever bears the Chalice bears Achievement. Each lofty deed can be marked by the symbol of the Chalice. Everything most lofty, everything for the good of humanity, should bear this symbol.
From the Teachings of Agni Yoga

Do not store up for yourselves treasures on earth, where moth and rust destroy and where thieves break in and steal; but store up for yourselves treasures in heaven, where neither moth nor rust destroys and where thieves do not break in and steal. For where your treasure is, there your heart will be also.
– Gospel of Matthew Verses 19-21