Deism - a type of monotheism which believes that a single god exists, who is personal in nature, but this god is presently not active in the created universe and the affairs of humanity. The term is commonly applied to those thinkers in the 17th and 18th century who held that the course of nature sufficiently demonstrates the existence of a god.  But for them formal religion was superfluous, and they did not believe in the claims of supernatural revelation.  Their tenets stemmed from the rationalism of the period, and though the term is not now generally used, the tenor of their belief persists.  The term freethinkers is almost synonymous.  Voltaire and Rousseau were deists, as were Benjamin Franklin, Thomas Jefferson, and George Washington. 
 
Polytheism - a belief system in which multiple gods are acknowledged and/or worshipped.  Usually, an individual god is a member of a larger, coherent group called a pantheon.  Polytheism typically involves the belief in several gods of a particular national culture.  Each individual god represents a unique value, personifies some aspect of humanity, and/or maintains stewardship over some facet of nature or society (e.g. Ares the God of War, Zeus the God of the Sky).  Examples include the religions of the ancient Egyptians, Greeks and Romans. 
 
Henotheism and Monolatry - are types of polytheism in which there is worship of just one god or primarily one god, but also acknowledges the existence of other gods.  In Henotheism one of the gods is elevated in rank to rule over the others but also to represent the nation or culture as a whole.  In Monolatry only one god is worshipped although the existence of other gods is accepted. 
 
Pantheism - the belief that everything, the totality of reality, is god.  That is, only god exists and all that exists is god (god = the universe). When scientific pantheists revere the universe, they are not talking about reverence for a supernatural being.  Instead, they are referring to the way human senses and our emotions force us to respond to the overwhelming mystery and power that surrounds us. 
 
Panentheism - the belief that a god interpenetrates every part of nature, but is nevertheless fully distinct from nature.  Panentheists and Pantheists share the view that the universe (that is, all of reality) is pervaded by divinity.  However, since panentheism postulates that the universe is contained within god and not god in the universe, panentheists believe in a god who is present in everything but also extends beyond the universe.  In other words, god is more than the universe.  Often they also believe that this god has a mind, created the universe, and cares about humanity personally.  Pantheists on the other hand believe that the universe itself is divine and do not believe in personal or creator gods. 
 
Animism - the belief that everything in nature, including living things like trees, plants and even nonliving rocks or streams has its own spirit or divinity.  The term animism is derived from the Latin word anima meaning breath or soul.  It is probably humanity's oldest type of belief system.  Many primitive tribespeople believe in animistic concepts (e.g. the American Indians). 

Paganism - this belief system may be pantheistic or polytheistic, but is distinctive in that it relates to a god primarily through nature. An example is Druidism. 
 
Shamanism - an animistic belief system of certain peoples of northern Asia in which mediation between the visible and spirit worlds is effected by shamans (holy people). 

Atheism - denial of the existence of a god or gods and of any supernatural existence, to be distinguished from agnosticism, which holds that the existence cannot be proved.  'A' means "without" and 'theism' means "belief in god(s)."  This is not to be confused with a hatred of God or an anti-Christian (or anti-theist) perspective, it is simply the belief that a god or gods or anything supernatural does not exist.  The term atheism has been used as an accusation against all who attack established orthodoxy, as in the trial of Socrates.  The 20th century has seen many individuals and groups professing atheism, including  Madalyn Murray O'Hair and Bertrand Russell. 
 
Agnosticism - a type of skepticism that holds that the existence of god cannot be logically proved or disproved.  'A' means "without" and 'gnosis' means "knowledge" -- hence, agnosticism: without knowledge (specifically: without knowledge of gods).  An agnostic is a person who does not claim absolute knowledge of the existence of a god or gods.  Since atheism and theism deal with belief and agnosticism deals with knowledge, they are actually mutually exclusive concepts.  It is then possible to be an agnostic and a theist.  A person can have a wide range of beliefs in gods and yet not be able to or want to claim to know for sure whether those gods definitely exist.  Prominent agnostics have been Auguste Comte, Herbert Spencer (agnostic realism), and T. H. Huxley (who coined the word agnostic in 1869). Immanuel Kant was an agnostic who argued that belief in divinity can rest only on faith.  Agnosticism should not be confused with atheism, which asserts that there is no god.