Theism is broadly defined as the belief in the existence of a supreme being or deities.[1][2] In common parlance, or when contrasted with deism, the term often describes the classical conception of God that is found in monotheism (also referred to as classical theism) – or gods found in polytheistic religions—a belief in God or in gods without the rejection of revelation as is characteristic of deism.[3][4]

God the Father depicted by Julius Schnorr von Carolsfeld in 1860

Atheism is commonly understood as non-acceptance or rejection of theism in the broadest sense of theism, i.e. non-acceptance or rejection of belief in God or gods.[5] The claim that the existence of any deity is unknown or unknowable is agnosticism.[6][7]