This is the bottom line: The cause of happiness is knowing Krishna, and the cause of distress is forgetting Him. A devotee who has found the cause of happiness will want to share his enlightenment with others. He is willing to pay that price in order to increase his happiness—by increasing the happiness of the Lord. If we compare the price tag of Krishna consciousness to the price tag of flickering sense gratification, we will realize that our austerity is insignificant.
(BG 6.32 Moscow, 1.8.97)