1,700 Years of the Nicene Creed
The Council of Nicaea, held in 325 AD, was the first major council of Catholic bishops, called by Emperor Constantine to address growing divisions in the Church, in particular a major conflict about the nature of Jesus Christ.
Why it was held:
A priest named Arius from Alexandria was spreading the false teaching that Jesus was not fully divine, but a created being: powerful and important, but not eternal like God the Father. This was causing so much division that the Emperor Constantine stepped in and convened the Council to try to restore unity.
Who attended:
Over 300 bishops from across the Christian world came to the city of Nicaea (in modern-day Turkey). Most were from the Eastern part of the Roman Empire, and smaller number of representatives attended from the West. One young deacon who attended was a man called Athanasius, who would later become a key figure in defending the Council’s decisions.
What happened:
The council debated whether Jesus was “of the same substance” (homoousios) as the Father or merely “of similar substance” (homoiousios). The difference came down to just one Greek letter—an iota (ι)—but it meant everything. That small letter represented a major theological divide: is Jesus truly God, or something less?
The Council firmly rejected Arius's false teachings and adopted what we now call the Nicene Creed, declaring that Jesus is "begotten, not made, consubstantial (of the same substance) with the Father."
Earlier creeds:
Before Nicaea, local churches used simpler baptismal creeds, like the Old Roman Creed (an early version of the Apostles’ Creed). But none of these directly addressed the controversy over Jesus' divine nature, which is why Nicaea marked a turning point. From these, however, we can see how the early Church held the same beliefs that we do today:
I believe in God the Father almighty;
and in Christ Jesus His only Son, our Lord,
Who was born of the Holy Spirit and the Virgin Mary,
Who under Pontius Pilate was crucified and buried,
on the third day rose again from the dead,
ascended to heaven,
sits at the right hand of the Father,
whence He will come to judge the living and the dead;
and in the Holy Spirit,
the holy Church,
the remission of sins,
the resurrection of the flesh
the life everlasting.
(The Old Roman Creed)
Aftermath and Saint Athanasius:
Though the Council officially condemned Arius, the conflict didn’t end. Arius still had powerful supporters. The young deacon, Athanasius, hadn't owned become Bishop of Alexandrai and he, strongly defended the Nicene position. For this, he faced years of opposition, was exiled five times for a total of 17 years, and became a symbol of perseverance for the sake of the Truth.
His fight gave rise to the saying: “Athanasius contra mundum,” (Athanasius against the world).
In short:
The Council of Nicaea was a defining moment in Christian history. It clarified that Jesus is truly God, not just a divine-like being. And it showed that, in theology, even “one iota of difference” can carry enormous weight.