Brihadaranyaka Upanishad
Yajnavalkya said to his wife Maitreyi, ‘Dear, the time has come for me to depart this worldly life and retire to one of meditation. I want to divide my worldly possessions between you and our family.’

Maitreyi said, ‘If I received all the wealth in the world, would it help me to become immortal?’

Yajnavalkya replied, ‘Not at all. You would live and die like any other rich person. Money does not buy immortality.’

Maitreyi said, ‘Then material possessions and money are not useful to me. Will you teach me the ways that lead to immortality?’

Yajnavalkya answered, ‘I have always loved you, but now I am overjoyed to hear you ask this question. Come sit with me and reflect deeply on what I am going to tell you.’

‘A wife loves her husband, but it is not for the love of her husband that her husband is dear, but for the Spirit that is in the husband. It is the same for children, wives, wealth, religion, power, animals, and everything else. Nothing is loved for its own sake – it is only the Self, or Spirit, that is loved. When this Self or Spirit is seen and heard in our thoughts and meditation, then we know and understand everything that exists.

‘When we hear music playing, we do not identify the individual notes separately from the tune. Only in the whole are the parts known. The Self or Spirit is that whole.

Only by knowing the Self can all the separate elements be known. When we live in a state if individuality, we can see and hear and feel and know another. But when we realize that everything is Spirit, and that Spirit is identical with one’s own Self, then how can we see, hear, feel and know another?

‘When a lump of salt is thrown into water, it dissolves and cannot be removed even though we can taste the salty water. So the separate soul dissolves in the sea of pure consciousness, infinite and immortal. Separateness comes when we identify the Self with the body; when this physical identification dissolves, the Self is no longer separate.’

Brihadaranyaka Upanishad