The principles of religion are laid down by the Lord Himself, and the executor of such laws is Dharmarāja, or Yamarāja. Such principles work fully in the age of Satya-yuga; in the Tretā-yuga they are reduced by a fraction of one fourth; in the Dvāpara-yuga they are reduced to one half, and in the Kali-yuga they are reduced to one fourth, gradually diminishing to the zero point, and then devastation takes place. Happiness in the world depends proportionately on the maintenance of the religious principles, individually or collectively. The best part of valor is to maintain the principles despite all kinds of odds. Thus one can be happy during the span of life and ultimately return to Godhead.