We Catholics walk a very thin line when it comes to the identity of our faith with that of the first generation of Christians. On the one hand, we believe that the Catholic faith has been handed down to us from Jesus and the Apostles and has remained intact to this day, but on the other hand, we have to admit that modern Catholicism looks very different from nascent Christianity. The first Christians almost certainly didn’t explicitly believe in things like the Assumption of Mary, papal infallibility, and transubstantiation (at least not in the exact same form we do), but those are all dogmas of our faith today.
So how do we reconcile this apparent incongruity? The key is something called development of doctrine. While we believe that the Catholic faith doesn’t change, we do acknowledge that it develops. If you’re not familiar with this idea, it may sound like mere semantic sleight of hand, but there’s actually a lot more to it. Let’s take a look at this notion and see how it can explain both the identity of our faith with that of the first Christians as well as the ways in which our faith is clearly different from early Christianity.
Like a Painting
To begin, imagine a person who owns a painting. The painting belongs to him, but when he first gets it, he almost certainly doesn’t know everything about it. There are probably going to be some details that he’s missed, and he most likely doesn’t understand everything the artist was trying to convey through it. However, over time, he might look at his painting and think about it more deeply, and in doing so, he’ll come to know it better. He’ll find more and more of those details that he missed initially, and he’ll better understand the meaning the artist was trying to convey through it.
And that’s exactly what development of doctrine is like. The Church possesses the deposit of faith handed down from Jesus and the Apostles, but our understanding of that deposit grows as we contemplate and study it throughout the ages. Simply put, development of doctrine is all about our growing and developing understanding of the faith, not about any change in the faith itself.
A Concrete Example
That may sound a bit vague, so let’s look at a concrete example: the Incarnation, the belief that Jesus is both God and man. Today, we have sophisticated theological terminology to describe this doctrine, but that language and the understanding it expresses developed over time. In the New Testament, we basically find only two essential points:
1) Jesus is God (John 1:1)
2) Jesus is a human being (1 Timothy 2:5)
And that’s pretty much it. Scripture doesn’t try to reconcile these two seemingly contradictory ideas, nor does it try to explain how Jesus can be both God and man. Instead, it simply presents both truths side by side. However, in the next few centuries, various controversies arose regarding Jesus’ identity (about both his human and divine sides), so the Church had to think more deeply about this mystery in order to understand it better.
For example, the Church came to see that Jesus is both God and man because he has both a human nature and a divine nature. In other words, he is 100% God and 100% man. He has all of the faculties by which God experiences and interacts with the world (that is his divine nature), and he has all of the faculties by which a human being experiences and interacts with the world (that is his human nature). Then, when more question arose, the Church had to clarify just what this entailed. For instance, the Church came to understand that Jesus has both a human intellect and a human will because intellect and will are essential parts of human nature. You can’t have a human nature without them, so Jesus must have them.
From the Beginning
The key here is that all of this development was simply a growth in our understanding of the faith that was there from the beginning. Already in New Testament times, the Church understood that Jesus was true man and true God, and everything that came afterwards was simply a growth in our understanding of what exactly that entails.
And the same is true with every other development of doctrine in the past as well as every development yet to come. Much like a man who owns a painting, the Church possesses the deposit of faith, and just as that man can grow to know his painting better, so too does the Church come to understand its faith better throughout the ages as she studies and contemplates it more and more. In this way, our faith can truly develop while also remaining the same for 2,000 years.