There is a story in Chhandogya Upanishad where sage Uddalaka teaches his son Shvetaketu about one essence of all that exists. He asks him to bring a fruit from the banyan tree. Then he asks him to break it open. There are tiny seeds inside. Uddalaka asks him to break one seed open. When father asks what is there, Shvetaketu replies there is nothing. Father tells his son that there is a subtle essence which is not seen but, but through that the immense banyan tree grows. You are that essence Shvetaketu
स य एषोऽणिमैतदात्म्यमिद सर्वं तत्सत्य स आत्मा तत्त्वमसि … (6.12.3).
That which is this unseen, this Self, this whole, is that Truth, is that Self, Thou art the That.
When you see a car moving, be aware that it is the combustion of fuel that is creating the moving force. Plants are silently drawing energy from the Sun and nutrients from the soil. And your breath keeping you alive. The life force is indeed subtle that keeps the gross up and moving.
Most striking is the power of thoughts, which can never be seen and yet make people do both incredible and terrible things. Then there are impulses and drives emanating out of your body and driving you to do things – both virtuous and harmful. Discerning between them makes the art of living.
Taittiriya Upanishad sees human as Brahman covered by five sheaths. These are: 1. the gross body – bone, muscles, organs, etc., made of food; 2. the energy body – breath, digestive system, and nervous system; 3. The mind body – our world of ideas, feelings and emotions; 4. intellect – our skills, knowledge, and wisdom; and finally 5. The feeling body. These are arranged one inside the other, with consciousness at the core and every outer sheath deriving its vitality from the inner one. In a beautiful imagery, the five sheaths are called the gatekeepers of heaven.
ते वा एते पञ्च ब्रह्मपुरुषाः स्वर्गस्य लोकस्य द्वारपाः (3.13.6).
These five Brahma Purushas are the gatekeepers of the heavenly world.
The Prashna Upanishad, in answer to the question who remains awake during sleep, tells that all the gross forms are described living upon the subtle Brahma just as the tree shelters the birds.
स यथा सोभ्य वयांसि वसोवृक्षं सम्प्रतिष्ठन्ते । एवं ह वै तत् सर्वं पर आत्मनि सम्प्रतिष्ठते ॥ (4.7)
As the birds fly towards the tree that shelters them, so does everything proceed towards the supreme Self to live.
Know that everything is living out of one essence, including yourself. This is the ultimate and most important knowledge. One who knows everything but not this, live and die like a fool.
परमेवाक्षरं प्रतिपद्यते स यो ह वै तदच्छायमशरीरमलोहितं
शुभ्रमक्षरं वेदयते यस्तु सोम्य । स सर्वज्ञः सर्वो भवति । (4.10)
By knowing the One who is without shadow, without body, without colour, and who is pure and imperishable, attains the supreme and the imperishable and becomes all and all-knowing. (4.10)
In the Bible, Jesus says, “The Kingdom of God can’t be detected by visible signs. You won’t be able to say, ‘Here it is!’ or ‘It’s over there!’ For the Kingdom of God is already within you.” (Luke 17:20–21, New Living Translation).
So, never feel alone, dejected, hopeless, and weak. You are a living part of the entire cosmos. Have patience and let the tough times pass over like a cloud. Stay grounded by minding your breathing when everything else appear out of control. In few moments you will see how subtle establishes control over the gross.