There are things no one tells you when you convert to Catholicism: that six-year-olds will know prayers you don’t; that you’re supposed to end every statement about a future contingent with “God willing”; and that you will feel the irrepressible urge to genuflect before leaving a room where something important has happened.

There are others as well, of course. Who knew that when someone says a saint’s name and pauses, you’re supposed to respond “Pray for us”? And why didn’t anyone ever tell me that when you’re blocking someone’s access to a holy water font on the way into church, you’re supposed to form a holy bucket brigade by letting him touch your wet fingers? Or that “Thank God” and “Awesome” can be used interchangeably when someone is telling you good news?

Adult converts like me will surely be familiar with the many minor moments of confusion that crop up at church and social settings where Catholics predominate. Even after almost fifteen years as a Catholic and six years as a vowed religious, there are still moments when everyone else knows just what to do or say and I don’t. It’s like being a citizen of a country you weren’t born in; sure, this is your home now, but that doesn’t make you a master of the culture.

That last comparison is key. Christianity in general–and Catholicism in particular–is not just a collection of rituals and dogmas. It is a culture. And, like all cultures, it becomes your own only after years of living immersed in it, not by merely memorizing practices and principles.

This is, I think, part of what Pope Francis is getting at in his recent exhortation Evangelii gaudium, where he talks about “the evangelizing power of popular piety.” When I hear the term “popular piety,” I often think about the sweet old ladies who would corner me after mass when I was in graduate school, foisting on me fistfuls of holy cards and devotional pamphlets they pulled out of their overstuffed purses, assuring me with utter confidence that God wanted me to become a priest, based on nothing other than their knowledge that I was a single man in my twenties showing up to daily mass (They won this round, I guess). Others might think of certain devotional practices like the rosary or the Divine Mercy chaplet. Yet others might think of nebulous, semi-superstitious practices like burying a statue of St. Joseph upside down in the yard of a house to be sold.

But none of these examples express the full reality of what the pope is talking about. He puts it quite nicely, if you would permit me the indulgence of a rather lengthy quote from Evangelii gaudium:

Once the Gospel has been inculturated in a people, in their process of transmitting their culture they also transmit the faith in ever new forms… Each portion of the people of God, by translating the gift of God into its own life and in accordance with its own genius, bears witness to the faith it has received and enriches it with new and eloquent expressions. One can say that “a people continuously evangelizes itself”. Herein lies the importance of popular piety, a true expression of the spontaneous missionary activity of the people of God. This is an ongoing and developing process, of which the Holy Spirit is the principal agent.

Here we have a theory of culture that is at the same time a theory of the Gospel and a theory about man. The Holy Spirit is not content to let the faith remain—as Pope Benedict put it in his encyclical Deus caritas est—an “ethical choice or a lofty idea,” something that sits atop the general life of a man as an added bonus. Because the faith is an “encounter with an event, a person, which gives life a new horizon and a decisive direction,” when we take hold of faith by God’s grace, God’s grace takes hold of us, reaching into every nook and cranny of our lives. Everything about us is now apt to be taken up and transformed in the light of Christ; the ongoing process of conversion that continues until the moment of our death is the means by which that grace gets woven into every concrete particular of our lives, until we can say with St. Paul and all the saints, “It is no longer I who live, but Christ who lives in me” (Gal 2:20).

But this is not just an individual process. What happens in the individual soul spills out into the whole community, such that each new group that encounters Christ lives out the consequences of that grace in its own way. Popular piety, then, is another way of describing the culture that the Holy Spirit brings into being through the particular temperaments, tendencies, presuppositions, desires, and needs of a given community. It involves every aspect of the person in the same way a national culture does, allowing members of the faith culture to express their love for God in big and small ways that are at once completely intimate and widely shared.

Like all culture, the culture of faith in one area may need pruning—especially where superstition or skepticism begin to grow—and not all of it will be equally congenial to every member of the community, even when there’s nothing wrong with a given practice (Don’t even ask me what I think about ending sentences with “God willing”).

But popular piety is an invaluable treasure, because it is a major part of how the faith becomes real, lived, incarnate in a given time and place. So, yes, adult converts like me can expect a whole lifetime of sudden cultural gaffes and lacunae, but in learning to let ourselves be changed by the faith that God has put in our hearts and in the hearts of those around us, we let ourselves “like living stones” be built into the “spiritual house” of God (1 Pt 2:5). And there at last we will find ourselves perfectly at home.

Image: Vasily Ivanovich Surikov, Boyarina Morozova
Author’s note: The image above represents the arrest of Morozova, an influential member of the Russian Orthodox sect, the Old Believers, who broke off from mainline Orthodoxy in the seventeenth century over certain small points of popular and liturgical piety, most notably making the sign of the cross with two fingers rather than three. The still-extant Old Believer schism points to the need to understand cultural incarnations of faith, in all their power and complexity.