Much like the Israelites of the Old Testament, the Aztecs believed they were the chosen people. They followed the command to search for their promise land, which came from a high deity, the god of war and sun, Huitzilopochli. Around 1116 A.D. they began a two hundred year odyssey from Aztlan to their final destination in the Mexico Valley. Following their god's command to dwell in the land where the eagle sits on a cactus, the Aztecs founded and engineered their capital city of Tenochtitlan.
Religion was an integral part of their lives and culture. They were people of much devotion and high mores. To stay the chosen people, they worshipped many gods with constant offerings. The offerings consisted of human sacrifice, and they practiced human sacrifice on a massive scale. The Aztecs believed blood nourished the gods and added to the stability of their cosmos. Believing divine forces that were in constant conflict and opposition to one another controlled the world, the Aztecs appeased the gods with the blood of sacrifice to keep order and balance in their universe.
The greatest gift offered to the god was the human heart. This was not an act of murder but the domain of their religion. Blood from the human heart fed the gods whom in turn allowed the Aztecs to exist in the world. They believed that the god of sun and war subsisted on human heart in order to rise and shine daily and also to help them be successful in war. The Aztecs believed sacrifice was an obligation for the common good. Because of this belief, there was high demand for the hearts of slaves and captives to be sacrificed. Frequently, they would make war with neighboring cities in order to capture live victims for their need to sacrifice. They also practiced cannibalism in their religion. Cannibalism was a religious ritual, a holy and sacred sacrament. Limbs severed from the sacrificial candidate (who is god-like because of the sacrificing) would be stewed in soup for the priest to devour; by ingesting the soup, the priest believed the likeness of the god would become part of him.