Why did the Aztecs think it was necessary to make blood sacrifices to the sun god huitzilopochtli?

The Aztecs believed that blood sacrifices were essential to sustain the sun god Huitzilopochtli, as they thought he fought daily against darkness to ensure the sun rose each day. They viewed these sacrifices as a way to nourish the deity, thereby securing cosmic balance and ensuring agricultural fertility. Furthermore, the ritual acts were integral to their religious and cultural identity, reinforcing societal cohesion and the power of the ruling elite.