An atheist, agnostic, humanist, secularist, or just a non believer.
If the capitalization of "God" means the question really is asking "What is a person who doesn't believe in my God?" the answer can be extended to include members of any religion other than yours (e.g. If you're Christian: Moslems, Sikhs, Hindus, Buddhists, Taoists, Pastafarians, Jains, Wiccans, Shintoists, etc.) Typically, one who does not believe in any deity at all is called an atheist. One who believes that it is impossible to know whether or not a deity exists is usually called an agnostic.
An atheist.
You may be looking for the term "athiest." An athiest is a person who doesn't believe in God. Various religions believe in God, but not necessarily that Jesus was God incarnate.
A person who does not believe in god is called a "Athiest"
christens believe in the trinity. God the father, God the son, and God the Holy Spirit. not to be mistaken, they believe they are all one person.
an athiest
An 'atheist'.
An atheist
an athiest
To be a theist is to believe in just 1 god.
An atheous is a person who doesn't believe in God.
Atheist
Atheist