Are all Humanists Athiest?
No, though many are, others prefer terms like agnostic, secularist, etc. Atheist means literally without belief in God(s) and refers to someone who emphatically believes that there are no reasonable grounds for belief in a religious entity of any kind. An agnostic is someone who believes that there is insufficient evidence for believing that there is a God but that there is a possibility that someone somewhere, some day may present a more convincing case for believing in God, and therefore aims to keep an open mind on the matter. Atheists are skeptical that any such evidence will ever be forthcoming. Humanists want to have the best possible foundation for their beliefs and values, and so they demand good evidence for all of their convictions, religious or otherwise. Since many Humanists don’t think the evidence for the existence of a God is very good, they are atheists or agnostics (people who haven’t committed to a definite belief) or pantheists (people who think the universe itself i