We don't talk about it enough but this one is a pretty clever joke. Humanity is always a selfish Petty creature trying to up itself from other species.

In almost all the religions, humans are depicted as a being born to be higher than other animals or other creatures (who knows maybe those things were added with bias by our predecessor)

It's the same with church of lucidion , it's a fantasy version of church (typical mediaeval church) we see in many fictions

Corrupt priests taking advantage of it , pulling the strings from behind etc. but Isekai Ojisan reverts everything it stands upon. Literally revealing the face of god in front of the person who thought he figured it all out, but lo and behold Ojisan being the translator of spirits debunking everything, church doctrine,beliefs, practice and sense of superiority.best part is

The priest was going to get broken by just thinking Spirit of life is the god, then he thought how they don't care about them, but turns out they do care ,but just on the same level humans treat worm or a pig, bigger disrespect than anything lol

It gets funnier when you remember other species like elves, orcs, goblin exists too . So even if Ojisan wasn't there to translate he would still be wrong!!

I also like to think it's a bit of jab to real church along the fictional ones. I mean a priest would definitely lose its mind IRL if they thing they worshipped their whole life turns out to be false/entirely different 

This is one of the best jokes from [Isekai Ojisan]