Today cities have become centers of pollution and unrest. There is pollution everywhere, as man's mind has become polluted. If mind becomes pure, everything else will become pure. So, cleanse your mind. Drive out all your worries. What is the use of brooding over the past? Past is past, forget it. Future is uncertain. What is the guarantee that you will be alive tomorrow? Don't worry about your future. Present is very important. This is omni present, not ordinary present. So, make the best use of present and be happy.
(From : Sai Veda, The Word of God, sayings of Bhagavan Sri Sathya Sai Baba)