"Constantine's acceptance of the Christian faith was the most important conversion in history, apart from that of the Apostle Paul" writes historian Nick Needham.

This Saturday, October 27, 2012 marks the 1700th anniversary of Constantine's conversion. Anniversaries help us to remember what God has done and to give thanks for his wondrous acts for his people. Why should we celebrate this day? 

Born in about 280, Constantine was crowned Caesar in York, Britain by his troops in 306 upon the death of his father. He controlled Britain, France, and Spain, and would soon vie for supremacy in the west with his rival, Maxentius, who controlled Italy and North Africa.

Constantine strengthened his forces and advanced to Rome, Maxentius’ capital. They met at the Milvian Bridge over the Tiber River, just outside of Rome. Maxentius' forces outnumbered Constantine's by perhaps two to one.

The Roman Empire was approximately ten percent Christian as he rose to power. The church had endured its fiercest persecution yet in the years 303-304 under Emperor Diocletian. Though the persecution had abated somewhat, believers still bore the visible marks of persecution in their bodies and lived with the threat of persecution. Constantine was generally tolerant to Christians, but Maxentius was not. Still, as the Christians watched these pagan titans square off, there was no reason to believe enduring relief would come soon.

But on October 27, 312, God changed Constantine and the world forever. He had been a worshiper of the sun god, and yet as he prepared for the battle of his life to come the next day, Constantine reported having a dream in the night. In that dream, he saw the Chi-Rho sign (the first two letters of the Greek word for Christ), with the promise "in this sign, conquer." Constantine believed he had received a sign from the God of the Bible, and commanded that his soldiers to place the Chi-Rho sign on their shields as they went into battle.

Constantine decisively defeated Maxentius the following day at the Battle of the Milvian Bridge. He attributed the victory to the Lord. Having conquered the west, Constantine, along with Licinius, emperor of the east, issued the Edict of Milan in 313 which granted religious toleration in the empire. For the first time, Christians had a legal right to worship the Lord and to serve Christ without fear.

Was Constantine converted that night? We cannot know what the Lord did then or know exactly when he was regenerated in heart (many question whether he was ever truly converted). The reality of the matter is that Constantine’s conversion probably took time. He continued to show some allegiance to the sun-god after this event, murdered his own son, struggled with vanity and tyrannical attitudes, and too-often supported Arians in later years (those not believing Jesus is eternally divine).

Yet, he did submit himself to the preaching of the word, seems to have shown indications of repentance for certain sins he committed, returned property to churches, helped build church buildings, and claimed to worship the God of the Bible. It is also significant that he was converted in spite of Christianity’s political insignificance at the time. He stood to gain nothing, humanly speaking, by becoming a Christian. So, how should we view him? Justo Gonzalez gives as good an assessment as possible when he notes that Constantine’s own statements indicate that he was a man who sought to serve God and was “a sincere man whose understanding of the Christian message was meager.”

Whatever happened in Constantine, we should give thanks for what God did through him. He granted toleration to Christians to worship God freely. If you are in the West and can worship God freely, you can trace that freedom, humanly speaking, back to Constantine. Constantine brought peace for the people of God across the empire as he expanded his rule. Through this peace, by the end of the century, over fifty-percent of the people in the empire claimed to be Christians. Not all were true believers, but it was still a wonderful time of gospel expansion in which many came to know salvation from sin and judgment. In the same century, there were apparently tens and even hundreds of thousands of Christians being put to death in Persia, but in the west, God’s people enjoyed peace. Most of us today trace our spiritual lineage through the west.

Constantine also worked to weaken the practice of infanticide and sought to create a more charitable and civil society. Christians had, since the resurrection, celebrated the Lord’s Day on the first day of the week, and in 321 Constantine recognized it as a day of rest for civil servants and those in commerce in his empire. Again, we can trace the blessing of the cultural expectation of this day of the week as a day of rest back to Constantine.

Volumes have been written about his other contributions to culture through his construction of Constantinople and in many other ways too great to recount here.

Finally, Constantine called the Council of Nicaea, which clarified the Scriptural doctrine of the deity of Christ. Many will quibble over how the council was called and that Constantine did not always support the decision of the council. Still, Christians today can give thanks for the clarity that was brought to the church. The church in this new era would gain greater clarity on many points because of the freedom afforded to exist, worship, think, write, and speak.

Like Constantine's Roman Empire, the United States is not a Christian nation. We are full of much sin ourselves, and yet, as in Constantine’s day, Jesus is building his church through the peace and stability afforded through this world power that has been so greatly influenced by Christians. We should labor for repentance and righteousness here, but let us not forget to give thanks for what the Lord is doing. Recently, I asked one African expatriate who is working to rebuild his homeland by building a Christian university there what more we could do after praying and giving. He surprised me by saying: “Be a good American.” He noted that the good that God is doing in Africa at the moment would not be possible were it not for the foreign policy of this nation, the training opportunities provided for expatriates, the economic strength, the technology afforded, the missionaries sent, and the knowledge and experience invested. People will debate what it means to be a “good American” as Christians. The point here, however, is that we should be rejoicing in the amazing things God is doing in our day in his providence through a world power.

Constantine died in 337. His legacy endures 1700 years later. Debates will inevitably rage about his life, his policies, and his legacy. But one thing is clear, Christ has been exalted greatly as a result of what God did through this remarkable man. For that, we must rejoice.

So, whether you plan a 1700th anniversary party for your neighborhood, or simply thank God for Constantine in private prayer, let us all glory in God’s holy name, rejoice in heart, and seek the Lord and his strength in our day. The Lord is still at work. Maybe he will be pleased to convert someone else this October 27 who will go on to change the world for the next 1700 years!