Monotheism is defined as the belief in one personal God. It may be contrasted with Poplytheism, or belief in many gods, and with monism, usually taken to mean that everything is really part of one impersonal absolute, like the Brahman of Advaita Vedanta Hinduism.
The three great Western religions, Judaism, Christianity, and Islam, see themselves as traditionally monotheistic. They all stem ultimately from the faith of Abraham and from the religion of ancient Israel. Another very important monotheist religion is Zoroastrianism, the faith of ancient Iran, which may have inﬂ uenced the Western monotheisms. It should also be pointed out that Hindu devotion to one of the great gods or Goddesses, such as Vishnu, Siva, or Devi, is generally actually monotheism of that deity, for though the worshipper may grant that the god may be worshipped under other names, it is honored as the one supreme sustainer of the universe. Another religion of India, Sikhism, is deﬁnitely monotheistic.
Monotheistic religion has a different character from polytheism or monism. By emphasizing one God, monotheism says that, despite appearances, the whole universe has one origin, one rule, and one center of meaning. Things do not work just by impersonal fate or laws of science, but ultimately by the personal will of a supreme intelligence. To many people this thought is very reassuring. Personal monotheism also says that people can have a close relationship with this personal God, as one would with another person, through loving prayer and service. Monotheisms tend to see God as male, or to use masculine language for God.
Monotheism also most often says that the personal God is the Creator of the universe. If God is in control of the cosmos through his personal will, at some point he must have started the process through a personal act of creation. Further, if the universe began at some deﬁ nite point, it presumably will end at some point in time, or rather at the end of time. This means that monotheistic religions usually take history seriously. They say it began through God’s creation and will end when his plan is completed, at a last judgment, and with the beginning of a paradisal world.
Personal monotheism also has God working in the world, in history, toward the accomplishment of his purpose. If God is personal, and can act freely in accordance with his will, it would be surprising if, having made the world, he did nothing to help it keep on track as it moves to the fulﬁ llment of the divine plan. Thus monotheistic religions generally say that God has indeed revealed himself within human history, through sending prophets and saviors, through sacred scriptures, through miracles and the divine guidance of his saints and the true religion. But because God respects the men and women he has made, these signs are not such as to override human freedom.
Monotheistic religions have then tended to emphasize God’s sovereignty, God’s will, and God’s action in history, and also human response through individual faith.