Final answer:
Monotheism is defined as the belief in one god, which is the foundation for religions such as Christianity, Islam, and Judaism. The best definition of monotheism is D. the belief in one god.
Step-by-step explanation:
The best definition of monotheism is D. the belief in one god. This is distinct from polytheism, which is the belief in multiple deities, and from atheism, which is the belief that there are no gods. Monotheism characterizes religions such as Christianity, Islam, and Judaism, where each religion centers on a single deity. Although some religious structures are complex, with sects or interpretations that might combine monotheistic and polytheistic beliefs, monotheism strictly refers to a religion based on belief in a single deity.
Monotheism is the belief in one god. It is a religious belief system that centers around the worship of a single deity. Monotheistic religions include Christianity, Islam, and Judaism. These religions believe in the existence of a supreme or all-powerful god. In contrast, polytheism is the belief in multiple gods.