The main religion practiced by the Aztec civilization prior to European colonization was polytheism, with a pantheon of gods representing various aspects of life and nature. The Aztecs engaged in elaborate religious ceremonies, including human sacrifices, to appease their deities and ensure the fertility of their lands. Key deities included Huitzilopochtli, the god of war, and Tlaloc, the rain god. Their religious beliefs were deeply entwined with their social and political structures, influencing daily life and the vast cultural achievements of their civilization.