How was Aztec religion like?

It depends what you mean. The Aztecs had any gods because they felt interconnected and at peace with nature. Everything that was significant in their lives was represented by a certain god or goddess. For example, their main diet consisted of corn/maize. And the maize god was Cinoteotl. Tonantzin was the equivlent to the virgen mary, Ometeotl was one of the equivalents of god, and so on.