The means to prolong or shorten one's life lie in one's own hands. Your life span is prolonged when you are full of joy, when you are calm and filled with pure thoughts. When you are filled with envy, anger, hatred and conceit, your lifespan gets shortened. The envious man gets no sleep at all. Sleeplessness ruins the health even more than lack of food. Envy torments a man all the time. These troubles lead to shortening one's life. As for hatred, the man filled with it cannot even bear the sight of his enemy. He suffers from hallucinations which consume his body and spirit. Anger is the cause of destroying the divine potencies in man. Hatred ruins a man's circulatory system. Envy drives the man crazy by depriving him of his sleep. In that condition, he cannot relish his food. Thus, these three evil qualities, hatred, envy and anger are wasting diseases. When you consider yourselves as devotees of God, you should get rid of these three evil qualities. Lead peaceful and pure lives. To call yourselves devotees but to look with envy at others is totally unbecoming. Exude joy always. That joy will manifest itself when you experience your oneness with the Divine within you. If you are unhappy, it is because you have not experienced the Divine.
(Sanathana Sarathi, August 1993, pg 203)
