The secret of radiant health and well-being is
Non-attachment,
which results in inner peace, the precursor of contentment.

Inner peace and contentment are not possible when we're attached to things being the way we want them to be. The ability to practice non-attachment enables us to purify the ego's hold on us, and this facilitates the soul's qualities of inner peace, joy and contentment to express in us. Non-attachment thus helps us to get rid of ego-blocks to the free flow of divine energy which flows through us, bringing us ever greater health and happiness.

During this month, practice noticing when you're attached to something being different than it is. Being aware of these times is half of the battle to learning to let go of attachments that don't serve to uplift us. Then experiment with different ways of "letting go" of these attachments. For example, you could offer them up to the Divine, saying you don't want to be attached to them anymore. Or, you could visualize yourself letting go of them into either a helium balloon, or into a fast flowing river. You could also visualize yourself honestly saying, "I am free!" (of this attachment). Or you could pray, "Lord, help me to accept that I will be happier and healthier when I learn to let go of this attachment."

– from Swami Kriyananda's Secrets of Radiant Health & Well-Being