Historians love dates—birthdays, anniversaries. They love to celebrate dates not simply for the sake of celebrating, but because dates represent events. Real events in the lives of real people, when real, significant things happened. Dates represent moments, and those moments can help us understand our own lives.

So, in the next five episodes, we will take a look at my top five favorite moments in church history.

The first moment is a date—325. I picked this date for several reasons. One, this is the date of the Nicene Council, out of which came that wonderful statement of Christian orthodoxy, the Nicene Creed. This date also represents a crucial moment in the life of the church.

Only a few decades before the Council of Nicaea, Christianity was illegal in the Roman Empire. In fact, the 290s and 300s were an intense time of persecution; almost an unprecedented time of persecution for Christians. Then came Constantine, and his so-called conversion—whether he truly converted is another question, but historians nevertheless speak of his “conversion.” In the wake of that conversion, in 313, he issued the Edict of Milan, which legalized Christianity. A few more edicts followed that contributed to the legality of Christianity—its being no longer an illegal religion, or as the Romans called it, an “illegal superstition.” Not only that, but Constantine also passed legislation that tended to favor churches and Christians, and within a generation, there was a massive spread of Christianity within the Roman Empire.

So, that brings us to the year 313. Just a dozen years later was the first great ecumenical council—the Council of Nicaea.

The council was called because of one man—a presbyter, or elder, named Arius. He had promoted the idea that Jesus is unique—that Jesus is beyond us human beings—but that He’s not God. And, of course, this gets right at the heart of orthodoxy: the statement that Jesus is the God-man. And so, Arius’ teachings were very disruptive within the early church. The bishops therefore came together to settle the matter for the church.

Nicaea is a wonderful city. Today, the city is called Iznik. It’s just off of Lake Iznik in Turkey. Constantine had a summer palace there. He invited all of these theologians to gather there in order to spend time working through these theological disputes, and the result was the Nicene Creed. In addressing this controversy, the council also gave us one of the best lines in theological literature. It is this simple line: “For us and for our salvation.”

Jesus is the God-man. His equality with God, as Paul tells us, is something that He did not have to grasp; rather, He had it already, and yet he took on flesh—He was made human—He became one of us. He didn’t simply appear to be human—He was human—and He was God. He is the God-man. And He is the God-man for us and for our salvation.