Monotheism (from the Greek: μόνος- One, and θεός -God) refers to the belief, found in a great many cultures, in a single, universal God. Many religions in the world are classified as monotheistic, and the preeminent examples are Judaism, Christianity, and Islam. Forms of monotheism can also be found in other religions including Zoroastrianism, Sikhism, and the Bahá'í Faith.