What's the difference between bitheism and theism?

Bitheism

Definition:

• (n.) Belief in the existence of two gods; dualism.

Example Sentences:

Theism

Definition:

• (n.) The belief or acknowledgment of the existence of a God, as opposed to atheism, pantheism, or polytheism.

Example Sentences:

• (1) The sketch that occasioned this lurch of theism on my part was a typical piece of Morrisian excess.