Someone who speaks on behalf of another--this is the literal definition of a prophet. The slang word is mouthpiece, often used to refer to lawyers because they speak for their clients. But prophecy is a religious term, and it refers to pronouncements made by individuals on behalf of a god. The best known of the prophets are those mentioned in the Hebrew Bible (or Old Testament)--Elijah, Isaiah, Jeremiah, Ezekiel, Amos, Hosea, and others. Prophecy, however, was not limited to ancient Israel. Evidence of it has been found in all religions, including Christianity, Islam, Hinduism, and animism.

It is often mistakenly believed that prophets mainly predict the future. While it is true that prophets have often foretold future events, their predictions were based on analysis of what they saw happening around them. Individuals whose main concern was in making predictions were called diviners. These were people such as astrologers, who studied the planets and stars for indications of future events; or they were people who read omens, such as the flights of birds, as a basis for predictions. The similarity between prophets and diviners was the belief that both received inspiration from gods. The first chapter of Jeremiah's prophecy, for instance, includes a verse in which God states: "Behold, I have put my words in thy mouth."

What a prophet had to say could come through visions or dreams, or it could be acquired by learning. Even the learning process, however, had a good deal to do with acquiring a mental state by which revelations could be received. Those who were training to be prophets were organized into guilds headed by prophet masters.

Prophets were distinguished from other religious functionaries by their sense of having a vocation, or calling, directly from a god. Priests presided over rituals, and teachers expounded doctrine; but prophets delivered a message, and it was frequently a message that contradicted traditional ritual or doctrine. Prophets were often critics of their societies, and, where they were successful, they were reformers. The preaching of the prophets usually had to do with justice and morality, calling on their audiences to mend their ways before their god punished them.

There were prophets in most of the societies of the ancient Middle East. Often they were simply advisers to kings. Sometimes they were asked to make predictions, especially regarding the outcome of military campaigns. In some cases they were affiliated with temples and were expected to deliver prophecies as a regular feature of religious festivals.

The best-known prophets are those whose work is described in the Hebrew Bible. Prophecy as a separate vocation developed slowly in Israel, and early examples were probably derived from neighboring Canaanite peoples. In the earliest period--around 1100 BC--there was no distinction between priest, diviner, and prophet. The early prophets were connected with sanctuaries at such places as Bethel and Jericho and later with the Temple in Jerusalem.

What is called classical prophecy appeared in Israel during the 8th century BC in the persons of Amos and Hosea. They are called classical for two reasons. Books that are reputedly their own writings, instead of reports about them, appear in the Bible. The emphasis of their prophecy was different; they expressed a hostile attitude to the prophets and gods of other religions, and they exalted a nationalistic concept of Israel's relationship to its god. Some of the prophetic denunciations were directed against an undue emphasis on rituals and sacrifices. The prophets insisted that God prefers upright and ethical behavior over slavish devotion to details of worship services. Because the prophets believed the people of Israel to be God's chosen people, they preached against anything Israelites did to compromise this relationship. This included the worship of other gods and alliances with other nations. Prophetic denunciations also included the abuse of power--the oppression of the weak by the strong--and the failure to administer justice. (See also Bible, "The Prophets.")

In most sects of Christianity Jesus is accepted both as the ultimate prophet and as the fulfillment of all previous prophecy. In the 2nd century, however, a new Christian prophet, Montanus, claimed to be the spirit of truth as prophesied by Jesus. Montanism spread among Asian and African Christians from AD 2 to 9 but was denounced as heretical by the pope. Several modern Christian sects follow the teachings of the ancient prophet Mormon, whose words, they believe, were divinely revealed to the 19th-century American prophet Joseph Smith.

Prophets played an important role in the creation of non-Judeo-Christian religions as well. For Islam Muhammad was the last of the prophets and the messenger of God who delivered God's final word in the Koran. Zoroastrians, who live in India and Iran, follow the teachings of the 7th-century-BC Persian prophet Zoroaster, or Zarathustra, one of of the earliest prophets of monotheism. Numerous prophets, such as Lakula, the founder of the Shiva sect of Hinduism, appear as spokesmen for the gods throughout Hindu oral and written traditions. In Native American societies, prophets or shamans served as spokesmen between man, gods, and nature.

The appearance of prophets in more recent history has often coincided with periods of great peril and social upheaval. In the 17th century, following massacres of Jews in Ukraine, Shabbetai Zevi, a European Jew, proclaimed himself the Messiah and last prophet and gained a widespread following. The messianic movement ended after Zevi, upon threat of execution, embraced Islam. Tenskwatawa, a Native American of the Shawnee tribe and the brother of Tecumseh, was revered as a prophet after he accurately predicted a solar eclipse in 1806. He led a resistance movement against United States expansion into Indian territory, but he lost his influence following a defeat in the battle of Tippecanoe in 1811. In 19th-century China, a Chinese convert to Christianity named Hung Hsiu-ch'uan claimed to be a prophet and the second son of God. He led the 14-year Taiping Rebellion against the ruling Ch'ing Dynasty. (See also Hinduism; Koran; Muhammad; Smith, Joseph; Taiping Rebellion; Zoroastrianism and Parsiism.)