Monsignor Charles Pope (Archdiocese of Washington DC) as always is on the money with some observations about churchy language.
one time I proudly announced, “RCIA classes will begin next week, so if you know anyone who is interested in attending please fill out an information card on the table just outside the sacristy door.” I thought I’d been perfectly clear, but then a new member approached me after Mass to inquire about the availability of classes to become Catholic and when they would begin. Wondering if she’d forgotten the announcement I reminded her what I had said about RCIA classes; she looked at me blankly. “Oh,” I said, “Let me explain what I mean by RCIA.” After I did so, I mentioned that she could pick up a flyer over by the sacristy door. Again I got a blank stare, followed by the question “What’s the sacristy?” Did I dare tell her that the classes would be held in the rectory?
The faith brings with it a new vocabulary. There are words like grace, mercy that have specific meanings in the context of the Christian life. There are things we do, like baptism, Eucharist, and things that are used to do those things, ambo, thurible. Specialized language allows us to be precise, but it can be confusing to the outsider, or for that matter, to many insiders. A few years ago I brought the class in to the church for a “Liturgical Scavenger Hunt”. Among the items they were to find were the Holy Water stoups. Our DRE at the time admitted she did not know that was what they were called. For my part, I mispronounced Collect for more than a decade after my conversion.
Part of what I do each Sunday is to give children the vocabulary of faith. I work with an age group that are word sponges. Give them a batch of new words and they pounce on them like a hungry lion. That vocabulary will serve them the rest of their lives.