Aztec Religion Sources

"Indeed, hardly a day passed by that [the Aztec] did not sacrifice from three to four, and even five [people], tearing the hearts out of their bodies, to present them to the gods and smear the blood on the walls of the temple. The arms and legs of these unfortunate beings were then cut off and [eaten], just in the same way we [c]ould buy meat from a butcher's shop and eat it: indeed I even believe that human flesh is exposed for sale cut up, in their [shops] or markets...

[The Aztec leaders said that] it would be impossible to [get rid of] their gods and the human sacrifices [because] everything that was good [the Aztec] received from these gods; they made their seeds grow and granted them all necessaries [of life]..."

Reference:

Díaz del Castillo, B. (1568).  The True History of the Conquest of New Spain. 

Context statement:

Bernal Díaz del Castillo was a Spanish conquistador, who participated as a soldier in the conquest of Mexico under Hernán Cortés. Before his death in January 1584, he wrote an account of the events of his life, called The True History of the Conquest of New Spain.

Copyright: Public Domain