A theist believes there is a God, an atheist believes there is no God, an agnostic is unsure if there is a God or not.
Part of Religious StudiesAn introduction to the philosophy of religion
There are three important terms to remember.
A theist is a person who believes in the existence of a god or gods - for example a Christian or a Muslim.
An atheist is a person who disbelieves or lacks belief in the existence of a god or gods.
An agnostic is a person who believes that nothing is known or can be known of the existence or nature of god.