You may be interested in the FAQ section on Spanish "Gods," as well as this comment from /u/Phefeon, which synthesizes a lot of the arguments (including some I've made at various points) against thinking the Americans believed the Spanish were gods.

First, that comment notes that our earliest primary Spanish source, Cortés' letters, has Motecuhzoma reassuring the Spaniard that the latter was human, just like Cortés. It also notes the origin of the "Spanish Gods" mythology as largely stemming from one major source, the Florentine Codex, the Christianized Nahua authors of which may have had their own reasons, both political and spiritual, for writing a history of the Conquest as divinely foreordained. Finally, it cites Townsend's "Burying the White Gods," the academic article which presents a wonderfully comprehensive look at, and dismantling of, the idea of the Spanish as gods.