The most widely used meaning of the word religion is probably the belief that a God or Gods exist who created the world, who is/are to be worshipped, and who is/are responsible for creating ethical and behavioral codes. In that context, Humanism is definitely not a religion, and would not be perceived as one by many people. Humanists do not generally believe in a supreme deity or deities, demons, ghosts, angels, in a supernatural world, in heaven and hell, or in a divinely ordained ethical code for humans to follow. Most would regard God as a creation of mankind rather than the reverse.

Religious Humanism has been loosely defined as religion with matters of faith and traditional belief deleted. Replacing these factors is a belief in humanity as the highest known form of intelligent life, and a belief in the scientific method as the best way to determine truth.

Many Secular Humanists feel that the role of religion throughout history has been so profoundly negative, that the word "religion" should not be connected to their philosophy.