Things and conditions can give you pleasure, but they will also give you pain. Things and conditions can give you pleasure, but they cannot give you joy. Nothing can give you joy. Joy is uncaused and arises from within as the joy of Being. It is an essential part of the inner state of peace, the state that has been called the peace of God. It is your natural state, not something that you need to work hard for or struggle to attain.

Eckhart Tolle

from The Power of Now: A Guide to Spiritual Enlightenment