The Isha Upanishad is one of the shortest and sweetest of all Upanishads. Mahatma Gandhi had said that if all Upanishads and all other scriptures were suddenly reduced to ashes and only the first verse in the Isha Upanishad survived, the heart of Hindu philosophy would still live for ever! This first verse which he spoke about is:
ॐ ईशा वास्यमिदँ सर्वं यत्किञ्च जगत्यां जगत् ।
तेन त्यक्तेन भुञ्जीथा मा गृधः कस्यस्विद्धनम् ।।
This verse represents the essence of the Upanishads. It says that Isha, God, the fundamental vibrations that sustain the universe, gives form to everything in the world. All things, living or non-living, material or abstract, in the past, present or future, real or imagined, are only manifestations of these vibrations and belong to God. Do not covet these things since they will never belong to you. You have come in this world empty handed, and you will leave it empty handed. You cannot own these things. You can only, temporarily, use them. Do not crave for them. Do not deny yourself happiness by becoming a slave to your desires!
Instead, renounce them and break the chains that bind your happiness. Renounce your desires so you can truly enjoy your possessions as a master of your will and not as a slave of your whims! Renounce the trivial and inconsequential to embrace that which truly matters. Renunciation is not denying yourself the good things in life. It is denying your hankering for them which only prevents your happiness. Happiness cannot be acquired by collecting possessions. It is a state of being that exists inside of you. Let your inner happiness shine forth. Renounce and rejoice in life!