The first commandment condemns polytheism. It requires man neither to believe in, nor to venerate, other divinities than the one true God. Scripture constantly recalls this rejection of "idols, [of] silver and gold, the work of men's hands. They have mouths, but do not speak; eyes, but do not see." These empty idols make their worshippers empty: "Those who make them are like them; so are all who trust in them." God, however, is the "living God" who gives life and intervenes in history.
-- CCC 2112