So would Orthodox Christians still see Constantine, and the notion of a Christian Emperor in general, as the way God wants his world to be governed? The idea that he is the ‘apostle’ of rulers would suggest that he is held up as setting the standard for the way all Christian lands ought to be ruled, wouldn’t it?
One has to see the context of the times.
(reading Eusebius might help)
Coming out of an age when Christians had been discriminated and many times cruelly persecuted for most of three centuries, his accession to the throne was nothing short of a miracle.
Of course, that was accompanied by the usual carnage that the empire faced when different people contended for the throne.
Now there was more than enough willingness to bring him down, he had many eneimies, and a conversion to, or even expressing a preference for the Christian minority (it was still a minority religion then) over the pagan deities which had sustained the empire for centuries was enough of a legal argument to depose him with a torturous end. He could have been considered guilty of the highest form of treason in Roman law and the right combination of enemies could have taken him down.
He was also the first emperor to not expect to be remembered as a god, or even be regarded a high priest of Rome.
To many Christians of the day, his arrival on the scene must have been seen as the providence of God, a true miracle, and new theories arose in Christian thought that had never been there before. Instead of being an apocolyptic church, looking for the end to this evil world and a release from it’s cares, some Christians began to think that God intended a single united Christian world order with the theocratic world empire encompassing everything. A ‘kingdom of God on the earth’. It was a new vision, an attractive romantic ideal and one of the reasons uniformity in Christian dogma became of paramount interest to the state.
Among other things, this was the origin of the old ‘divine right of kings’ which plagued European history for many centuries with some of the worst possible characters one can imagine in charge of anything.
So of course, the reality of this new model of Christian world fell far short of the ideal, and the old empires are all gone. We can now look back on it and see that perhaps this was not at all what God had in mind.
But the powerful personality of this man shines through as one of the remarkable characters of Roman, indeed of world history. He truly did make it possible for the church to save many souls, at the risk of his own.
BTW, Saint Constantine was not the only one to receive the honorific title of “equal to the Apostles” in an Orthodox understanding. There have been others, including the Samaritan woman at the well and Saint Patrick of Ireland.