Human sacrifice probably had a lot to do with social order and maintaining a highly stratified society. Before a king took office, there was probably a sacrifice. Since other sacrifices were for gods, this made the king less of an ordinary human. It is thought that wars were waged to provide sacrificial victims. Providing victims would make the wars more justified. Presumably there was a promise made at the start of the battle that if a certain god permitted the praying city to win, the city would repay him with human blood from the losing city.
For now, the motives ascribed to the Maya for their human sacrifice center on the idea that the Maya thought their gods required it to maintain the order of the universe. A myth of the creation reveals that a feathered serpent brought time from the Underworld to humans. The feathered serpent is marked with a calendar, human sacrifice, and rulership. The sacrifice was a form of repayment for this gift from the Underworld. The Maya may have employed a sympathetic magic in their human sacrifices when they put humans down a well during a drought.
The sacrifice of humans, in general, was probably thought to feed the deities.