At the point Christ came, the true faith had been kept alive up to that point, after a fashion, among the Jews. I say it was kept because of the many faithful believers among them who were looking in true faith for the Messiah. Jesus Himself said that Israel had teachers who sat in Moses’ seat, and who should be respected, at least to a point. I say “after a fashion” for another reason. The downside, obviously, is that the leaders of Israel conspired to have their Messiah executed in a rigged trial. So the state of the world was pretty bad when Christ arrived — the whole world was under the control of demonic darkness (1 John 5:19), and the Jews had made their peace with this arrangement. The harlot rode the dragon.
When Jesus rose and ascended, His disciples did not return to the upper room and unpack Christendom from the boxes He had left for them there. As has been pointed out repeatedly, Jesus did not give them a turnkey kingdom. The kingdom of God does not arrive as coup de main. The kingdom of God does not arrive like a tsunami. The kingdom of God does not arrive like the 101st Airborne. Jesus said, and He said repeatedly, that the kingdom was a slow growth affair, working through the loaf like yeast.
And now, two thousand years later, when we see that the Christian faith has grown and expanded throughout the world in just the way He said it would, should this be a cause for unbelief?
In retrospect, we can see the milestones we passed in the journey to the first Christendom, and future historians will be able to point to milestones in our era that marked our passage to the resurgent Christendom. But one of our current problems is that we are a convenience store civilization, and we want the next iteration of our civilization to be obtainable the same way we get coffee at the convenience store. We want to plonk our two dollars on the counter, and walk out of there with the coffee.
If somebody, a madman with a blog, say, says that if Jesus is the Savior of the world, this might necessitate the world getting saved, he is answered with demands that show us the constituent building blocks of Christendom now. We want to knock on them with our knuckles. We want to squirt the mixed metaphor flavor in from the pump jar, and drink the coffee now. We want the world to become Christian the way the devil offered to make it Christian, if only Jesus would bow down and worship him.
But God works a different calculus, and He had His only begotten Son hanged on a gibbet instead. What was He doing? He was making the world Christian, but He was doing it His way and on His timetable. But He was making the world Christian (John 12:31). Jesus, by and through His death, cast out the prince of this world. And, by the way, in the original Greek “cast out” does not mean “kept around.”
With the vantage of centuries past, we can look back and see that when Ambrose had his famous conflict with Theodosius, this was a great moment in the formation of Christendom. But at the time, I doubt if Ambrose had any idea of what he was doing — except standing faithfully at his post. And in the development of Christendom, we do not just see the church putting the magistrate in his place. It goes the other way as well. Frederick, Elector of Saxony, protected the gospel when the Church had decided to quit doing that, and opted for attacking the gospel instead.
So how is the process of discipling the nations to be accomplished? With centuries, nay, with millennia of bumpity bumpity.