Books You Haven't Read But Should: High Aztech by Ernest Hogan

In mid 21st century Mexico the ancient gods are worshiped again in the mighty city of Tenochtitlan. Human sacrifice is coming back into fashion, especially on the new Aztechan TV channels, and everyone wants an artificial heart. Xolotl Zapata, celebrated poet, skeptic and songwriter, starts receiving death threats from a cult he's lampooned in a comic book, but his problems really start when he catches a religious virus, and then everybody is out to get him.

Here's a good review by Justin Case:

Science Fiction or SF - never Sci Fi - sometimes speculates on religion and it's themes. That's where the original inspiration for the Church of All Worlds comes from. Writers work with this subject in different ways, often to make a point, rizzoa some stuffed shirts, and have some fun and make some dineroas well. "High Aztech" tries to to exactly that - puncture some xixtatl heads, ocotitia (cause discord) and have some fun doing it.

By 2045, the World has been through an Armageddon of sorts, and TenochtitlAn is in the midst of a Neo-Aztecan revival; sponsered by High Aztech S.A., a heart transplant Clinic/Temple, and the most popular song is "Huitzilopochtli Eat My Heart. XOlotl Zapata, a cartoonist named after some ugly Meso-American god before the general practice of taking an Aztec name became radioactivtl. His problems really began when he drew a cartoon, "Teoguerrilas", which ridiculed some of the street gangs who styled themselves as Aztec Knights. So the Neliyacame Thugitome, or little thugs, want him in MictlAn (Hell) or at least to colotl him in the ahuilotes.

At the same time he's having trouble with his yolotli (lover), and sometimes brujatl, who hypoed him with a highly contagious Aztec religious virus - which makes him an instant convert and carrier. This is Witnessing with a PUNCH ! Later she's found murdered and he finds imself a "guest" of High Aztech as the prime suspect. His mother, a government curadera infects the piligUetl with all the other viruses the government either discovered or seized as conraband - except the Fundie virus which the Fundies gladly "shared" with him later. After he's freed, he wanders around in a visionary haze with many contrary and absurd Commandments dancing in his head. Since he's a virtulent carrier he infects a large part of the city all by himself, and the masses, filled with visions and portents, await the End of the World. Finally, the viruses begin to cancel each other and he regains some rationality - but by that time he's quite Lost - in more ways than one...

A man finds him and destroys a electronic bug that was following XOlotl throughout the city and keeping track of him for Aztech assassins. He is taken to the "TICMOTRASPASARHUILILI !" - the terrorists responsible for the plagues, and their philosophy of "You will pass it on to someone", whose goal seems to be the eradication of Religion.

Its a fun romp, and the book makes some interesting and funny observances along the way - and you will learn some Neo-Aztec as well Its themes of forced conversion, whether any religion can be the True one, and whether people really have free will are quite serious ones.