The Mesoamerican concept of god and religion were very different from the current western concept. To the Mesoamericans, everything, every element of the cosmos, the earth on which mankind lives, the sun, the moon, the stars, everything that forms part of nature such as animals, plants, water and mountains all represented a manifestation of the supernatural.
Quetzalcoatl, the feathered serpent
In Mesoamerica, gods and goddesses are often depicted in stone reliefs, pottery decoration, wall paintings and in the various Maya, Aztec and Mixtec codices. The spiritual pantheon was vast and extremely complex. Amazingly, many of the deities depicted are common to the various civilizations and their worship survived over long periods of time. They frequently took on different characteristics and even names in different areas, but in effect they transcended cultures and time.
Great masks with gaping jaws and monstrous features in stone or stucco were often located at the entrance to temples, symbolizing a cavern or cave on the flanks of the mountains that allowed access to the depths of Mother Earth and the shadowy roads that lead to the Underworld.
Jade cults in Mesoamerica
Cults connected with the jaguar and jade especially permeated religion throughout Mesoamerica. Jade, with its translucent green color was revered along with water as a symbol of life and fertility. The jaguar, agile, powerful and fast, was especially connected with warriors and as spirit guides of shamans.
Despite differences of chronology or geography, the crucial aspects of this religious pantheon were shared amongst the people of ancient Mesoamerica. Thus, this quality of acceptance of new gods to the collection of existing gods may have been one of the shaping characteristics for the success during the Christianization of Mesoamerica. New gods did not at once replace the old; they initially joined the ever growing family of deities or were merged together with existing ones that seemed to share similar characteristics or responsibilities.
What type of religion would be practiced in Mexico if the Spaniards would not have forced Catholicism on the people in the area
This is a verry good and relevant question. Unfortunately, history is often written by the victors. We will never know. It is however fascinating to learn from the ancients.
I Like you blog, it is interesting.