The main difference is one Latin word: filioque, meaning “and the Son.” Catholics added it to the Nicene Creed in the section about the Holy Spirit. We didn’t.
The Orthodox Creed says the Holy Spirit “proceeds from the Father.” That’s what the Ecumenical Councils of Nicaea (325) and Constantinople (381) gave us. The Catholic version says the Holy Spirit “proceeds from the Father and the Son.” It sounds like a small change. It’s not.
What happened
The addition started in Spain around 589 at the Third Council of Toledo. The Visigoths were dealing with Arians who denied Christ’s full divinity, so they added “and the Son” to emphasize that the Son is equal to the Father. Fair enough as a local response to heresy. But then it spread.
Charlemagne’s Frankish kingdom picked it up in the 8th century. Rome resisted for a while, early popes actually opposed changing the Creed. But by 1014, under political pressure, Rome officially adopted the filioque in the liturgy. The Orthodox East never accepted it. We still don’t.
Why it matters
This isn’t about being picky with words. The theology matters.
Orthodox Christianity teaches that the Father is the sole source of the Trinity. The Son is eternally begotten from the Father. The Spirit eternally proceeds from the Father. Each Person has His own distinct property, and the Father alone is the unoriginate origin. That’s how the Trinity works without collapsing into confusion or hierarchy.
When you say the Spirit proceeds from the Father “and the Son,” you’re giving the Spirit two sources instead of one. That muddies the waters. It risks making the Spirit somehow less than the Father and Son, or it blurs the distinct persons together. The Father’s monarchy, His role as the one source, gets compromised.
St. Photios the Great wrote extensively about this in the 9th century, and his concerns still stand. The filioque changes how we understand the relationships within the Trinity itself.
The authority problem
There’s another issue beyond theology. The Ecumenical Councils forbade anyone from altering the Creed. The Council of Ephesus in 431 made this explicit. You can’t just add words to what the whole Church agreed upon in council.
Rome added the filioque unilaterally, without calling an ecumenical council or getting the East’s agreement. From our perspective, that’s not how the Church makes decisions about faith. We believe in conciliarity, the whole Church discerning truth together, not one bishop or region changing things on their own.
This gets at a deeper divide about authority that contributed to the schism of 1054. But even if Rome had the authority Catholics claim, the theology itself is the real problem.
What we say instead
When you come to St. Michael’s and hear the Creed, you’ll hear the original words. “And in the Holy Spirit, the Lord and Giver of Life, who proceeds from the Father, who together with the Father and Son is worshipped and glorified.”
The Spirit proceeds from the Father alone. But He’s sent into the world by the Son. He rests upon the Son. He reveals the Son to us. There’s a relationship there, absolutely. But procession, the eternal relationship within the Trinity, is from the Father only.
If you grew up Catholic, this might feel strange at first. You’ve been saying “and the Son” your whole life. But the Orthodox Creed is older. It’s what Christians everywhere said for the first thousand years, before the addition took hold in the West.
Fr. Thomas Hopko used to say that the filioque is where theology and history crashed into each other. He was right. This one word represents different ways of understanding the Trinity, different ways of making decisions as a Church, different paths that East and West took.
When you learn the Creed without the filioque, you’re not just learning different words. You’re entering into the faith as the Apostles handed it down, as the Fathers defended it, as the whole Church once confessed it together.
