You might consider this a sequel to a past question I've had, except instead of teaching them how to be artists, it's teaching them how to be devout in whatever you follow. For the sake of respecting technicalities, the loosest definition of religion/ideology/politics will be used here, which is incidentally a definition where they have historically overlapped.

I have relatives who have mental challenges, and this question is inspired by my wonder all the time as someone who has lived much of his life in a very zealous religious community who has observed local missionaries (everyone is a missionary in this small town) try to get creative trying to teach the gospel to people who couldn't comprehend how an airplane works. Some of them have taken notes from psychologists and used toys inspired by the psychologists' usage of Mr. Potato Head toys to diagnose autism (not sure if they still do that), others have simplified the gospel into some extremely simplified analogies, made to fit the language model inside these individuals' minds, which both almost makes it resemble a cargo cult at times as the method used often has them using, for example, objects and their lack of object permanence as an allegory for prophets. So on and so forth. It's both fascinating and terrifying, but it begs my question when it comes to interspecies communication which is an interesting topic.

Suppose you absolutely had to do this, either for some consequentialist social reason or maybe for an experiment to see if adherence would be possible. What method would you perform?