This Krishna consciousness is so nice, the more one works and renders service, the more he becomes enthusiastic. This is the secret of spiritual life. The test of spiritual life is when one can work all day long and not be tired. In the material world, we do a little work and become exhausted. 24 hours we should be engaged in some service to our capacity. That is real spiritual life.
Letter to Hamsaduta, 24 April, 1972