Amazonians are too stupid [don't have the language] to understand Catholicism

It is Sapir-Whorf.

https://en.wikipedia.org/wiki/Pirahã_language

for example, this tribe's language, and thus themselves, barely have the capacity to describe something that has not been seen by the speakers.

A group of men at this other village said, “Dan, so tell us a little bit more about Jesus. Is he brown like us or is he white like you? And how tall is he? And what sorts of things does he know how to do? Does he like to hunt and fish and stuff, or what does he do?”

I said, “Well, you know, I don’t know what color he is, I never saw him.” “You never saw him?” “No.” “Well, your dad saw him then,” because you can give information that was told to you by somebody who was alive at the time.

I said, “No, my dad never saw him.” They said, “Well, who saw him?” And I said, “Well, they’re all dead; it was a long time ago.”

“Why are you telling us about this guy? If you never saw him, and you don’t know anyone who ever saw him,” and those are the two basic forms of evidence for the Pirahã.

They don't have numbers, the word "Trinity" means less than nothing.

And who knows how missionaries butchered both cultures to get them to convert in the first place:

So Richardson was really confused. How could he get the message of the gospel across to a people who thought that Judas was the hero of the story? Then he realized that they had wars with neighboring tribes, and he found out that the way they stopped the wars was for one person from one tribe to give a baby to a person in the other tribe, and they called that the peace child. (I’m basing everything I’m saying on his description, whether it’s right or wrong. I often find that when I double-check the anthropological literature much more carefully, these descriptions don’t work out to be that accurate. But forget that; let’s just take it at face value right now.) As long as that peace child lived, there would be no war between the tribes. Richardson said, “Aha, I have it now. Jesus is God’s peace child.” And so he told them that Jesus was the peace child from God and that Judas killed the peace child. So now they don’t like Judas, and they began to convert to Christianity in large numbers.

After I came back, a Pirahã guy said, “I used to want to go to town, but I don’t want to go to town anymore. I wanted to see how Brazilians live but I don’t want to go there anymore.” “Why not?” “Well, this guy came and he said that this guy he said was God and Jesus wanted me to go to town, and they were going to put me in a building that I couldn’t get out of, and they were going to kill me, and take me to heaven.”