The First Commandment
You shall have no other gods before me is the first of the 10 Commandments, which prohibits the worship of any god other than Yahweh, the God of the Israelites. When the 10 commandments were given by God through Moses, the Israelites were were coming out of Egypt, whose religious beliefs included worshipping many gods, and they were destined for the land of Canaan, whose residents had a worldview that also included worshipping many gods. Unlike certain "chief" gods in polytheistic worldviews (i.e. the beliefs in more than one god), Yahweh wasn't just demanding first priority, but absolute exclusivity, so to revere any other god was sinful, according to the first commandment. This commandment continues to be observed in the Jewish religion.
What is the Scripture reference? Exodus 20:3, "Thou shalt have no other gods before me" (KJV); “You shall have no other gods before me" (ESV); "You shall have no other gods before Me" (NASB); "You shall have no other gods before me" (NIV) What is the relationship focus? People and God (commandments 1-4 emphasis people's relationship with God) Is the commandment a prohibition? Yes (the commandment is saying what "must not be" done, as opposed to what "must be" done)
This commandment establishes the exclusive nature of the relationship between the nation of Israel and its national god, Yahweh the god of Israel, a covenant initiated by Yahweh after delivering the Israelites from slavery through the plagues of Egypt and the Exodus. In a general sense, idolatry is the paying of divine honor to any created thing. In ancient times, opportunities to participate in the honor or worship of other deities abounded. However, according to the Book of Deuteronomy, the Israelites were strictly warned to neither adopt nor adapt any of the religious practices of the peoples around them. Nevertheless, the story of the people of Israel until the Babylonian Captivity is the story of the violation of the first commandment by the worship of “foreign gods” and its consequences. Much of biblical preaching from the time of Moses to the exile is predicated on the either-or choice between exclusive worship of God and false gods.
The Shema and its accompanying blessing/curse reveals the intent of the commandment to include love for the one, true God and not only recognition or outward observance. In the gospels, Jesus Christ quotes the Shema as the first and greatest commandment, and the apostles after him preached that those who would follow Christ must turn from idols. The Catholic Catechism as well as Reformation and post-Reformation theologians teach that the commandment applies in modern times and prohibits the worship of physical idols, the seeking of spiritual activity or guidance from any other source (e.g. magical, astrological, etc.), and the focus on temporal priorities such as self (food, physical pleasures), work, and money, for examples. The Catholic Catechism commends those who refuse even to simulate such worship in a cultural context, since “the duty to offer God authentic worship concerns man both as an individual and as a social being.”
Wikipedia, the free encyclopedia (with minor edits), under GFDL