What is a theist?

In the most common understanding today a theist is one who believes in a power higher than themselves.  These fall into several groups.

Judaism, Islam and Sikhism are monotheistic, or religions of only one God.  Muslims refer to God as Allah and share many revered prophets with the Jews such as Abraham, Moses and Jesus, though they deny Jesus as the son of God.  Sikhs refer to God as “Parmaysher” (spelled phonetically) and their prophets are the gurus.  The God of the Jews has a name but through superstition they ceased using it long ago.

Modern Christendom has a triune God; the Father, the Son and the Holy Spirit.  Though because of the hundreds of fractions in Christendom today a consensus on this subject is difficult to come by. 

Various cultures that might be considered “primitive” usually believe in multiple Gods or spirits, often inhabiting animals and other forms of nature.  They seek to live in harmony with these spirits by means of rituals and sacrifices.  Hindus, though not primitive, take the belief of multiple gods to the extreme.  Their faith acknowledges the existence of over 300 million gods. 

The common thread between these religions is the belief of a higher power, though who that power is and what they expect from their worshippers vary widely.

If we take the word religion in its broadest form, that of a system of belief, we can include many other religions.  Buddhism would be one example.  Siddhartha Gautama (Buddha) rejected belief in God as a creator but didn’t completely discount the possibility of his existence.  Buddhists are trying to achieve Nirvana, a releasing from a life of pain.

The world’s largest religious groups are Christians (by totaling all their fractions), Muslims and Hindus. 

If we continue with the definition of religion as a system of belief held to with ardor then there is one other group we can include.

Atheists.