I won't spent a lot of time on the details of Diocletian and his Great Persecution. We have a higher goal than the details.
The Great Persecution, from A.D. 303 to 311, was a time of sudden transition and massive change in the history of Christianity. It's the change and what caused it that we want to focus on.
To do so, I want to rename the Great Persecution and give you my unique (but historically accurate) perspective.
Let's call it ...
I took judo for several years as a child. Even though I was very small, I was pretty good at it. In Judo, you don't have to be stronger than your opponent. Instead, you make your opponent's strength work for you.
I must have had a good teacher because I remember lots of surprise on the faces of larger kids as they crashed to the ground.
There's a secret to getting your opponent to help you throw him.
You push really hard. Your opponent automatically pushes back.
When they push, you pull and rotate into a throw. It's amazing how far their momentum will carry them.
Though it's popular to believe that Christians were always being persecuted in the Roman empire, it's not true. Empire-wide persecutions were rare, and the Great Persecution under Diocletian was the only one of any great length, lasting eight years.
It was intense. Diocletian's goal was to wipe out the Church. He hunted down Christians and their Scriptures. He especially loved to get hold of church leaders.
He was trying to turn them back to paganism, to the old Roman religion with the emperor as a God. Therefore, anyone he caught and tried could be released by offering a sacrifice to the gods or to the emperor.
They could also gain great favor by turning over copies of the Scriptures to be burned.
In addition, Diocletian destroyed their church buildings. This was something that couldn't be done earlier, as Christians rarely had devoted meeting places in the 2nd century. It was too easy to see them destroyed or taken over. While empire-wide persecutions were rare, local persecutions at the whim of a governer or prelate were not.
It was a horrible, difficult time for Christians (at least for the leaders). Many Christians fell away, and many others were tortured, thrown in a dungeon, or put to death.
By 311, Galerius could no longer stomach the attack on the church. Along with Constantine and Licinius he issued the Edict of Toleration, ending the Great Persecution.
In A.D. 312, Constantine the Great marched on Rome and took part of the empire from the co-emperor Maxentius. That left himself and Licinius as co-emperors, Galerius having died of a terrible disease in 311.
Constantine and Licinius added their Edict of Milan in A.D. 313. It went further than Galerius' edict, not only ending persecution, but restoring privileges and property to Christian leaders.
This was sweet victory for the Christians. They welcomed Constantine the Great with open arms. He bestowed favors on them, and he surrounded himself with bishops. In every way, they received him as a Christian.
But he wasn't one, and they shouldn't have.
Constantine the Great eventually took the rule of Rome from both Galerius and Licinius, finally defeating Licinius in a civil war in A.D. 324. The following summer he presided over the Council of Nicea.
Constantine didn't fool the church by calling himself a Christian. He didn't try to. He remained high priest over the pagan religion. He was a great emperor from a worldly standpoint. He did not want conflict between the Christian and pagan religions to divide his empire.
However, Christianity was clearly his favorite religion, and he was highly involved in the dispute over the Trinity that hit its height at the Council of Nicea. He participated in those disputes and appointed and removed bishops, occasionally expelling ones he considered heretical from the empire.
As I said, the Church embraced his intervention and even praised him as an angel sent from God for their protection.
They also embraced the masses of unconverted pagans who entered Christianity behind him. Philip Schaff, the great historian, writes:
I have always said that the effect of this influx of unconverted pagans who were simply joining a national religion can be best seen in the compared histories of Eusebius and Socrates Scholasticus. Eusebius wrote his Ecclesiastical History in A.D. 323, while the Church still basically possessed the Christianity of the apostles. Socrates Scholasticus wrote his around A.D. 440 and covered the time after Eusebius' history.
The differences are simply astounding. Eusebius writes about godly church leaders, doctrinal controversies, and martyrs. Socrates writes about bloodshed, violence, political intrigue, and envy.
The Church was fallen.
Diocletian (and afterwards Galerius), with the Great Persecution, pushed on the Church, Constantine did the pull, turn, and throw. The Church crashed to the ground. It has never fully recovered. No history like Eusebius' can be written again. The Anabaptists of the early 16th century, the Moravians and Waldensians of the 14th century, and many others have a similar history. All, however, had much less influence than the apostles' churches of the 2nd and 3rd centuries.
Around such glorious lights is massive darkness. The darkness was so great that the cooperative rule of Rome and Church beginning (for the most part) after the end of the Diocletian persecution is known as the Dark Ages.
How bad is it when even the world calls the influence of the Church darkness?
Christianity, in its pure state, was powerful. Tertullian testifies:
Throughout the 2nd and 3rd centuries, the devil found out that what Christ had said is true. He built his Church, and the gates of hell could not prevail against it. Tertullian adds:
Diocletian's force was completely ineffective against the Church and the power of a message that was lived out. But where force is ineffective, often Judo can be very effective.
It was not the force of Diocletian or the Great Persecution that was effective against the Church. It was the embrace of the world that made it fall. May we shake ourselves from its arms, rise up, and seed the world again with the purity that the apostles left in their churches.