How did the Greeks worship? The ancient Greeks lived in many separate city states. Each was run in different ways. Sometimes, the city states fought each other. But they shared the same religion and language. Religion was important to all ancient Greeks. They believed in many different gods and goddesses, who could affect life on earth. The gods and goddesses had to be worshipped to keep them happy. As part of this worship, the ancient Greeks built beautiful temples as homes for the gods.