When people try to convince you that their religion is true because of completely superficial issues, that’s a good indication that the other person’s faith does not have much of a firm foundation in the first place.
I really do mean that. When someone says “you can’t be the Church founded by Christ because when I look in the yellow pages, you’re listed under “c” for cathedral instead of “t” for temple” you can be sure that the person’s faith-community is not based on any genuine, deep, reasoned theology.
Having said that though, I’d suggest caution on bringing that into the conversation.
First of all, we can and sometimes do refer to Catholic church-buildings as temples. A temple is a place where the sacrifice occurs. It’s entirely acceptable to call a Catholic church by the word “temple” although in everyday language, we usually don’t do it. It’s very common, however, in Eastern Catholic/Orthodox use to use the word temple.
In canon law, there are different types of buildings. We have churches, oratories, chapels, cathedrals, shrines, basilicas etc. Because these different kinds of buildings have different uses, we have words for each of them. It’s no different than the fact that we sometimes use the word “tree” while other times it’s important to say “oak tree” or “pine tree” or “apple tree.”
The word cathedral has its own history. I won’t type it out, but you can read it here:
The topic of prophets is much more important.
We do not have prophets anymore because all of the prophets pointed toward Christ Himself, and now that the Incarnation has already happened, there is nothing more to announce AND because Christ Himself is the last and pre-eminent of all the prophets.