Chesterton on Eastern Christianity in Jerusalem

I really liked Chesterton's remarks here, they are rather damning of European Christianity. After this quote he goes on to say, basically, that Western Christians would have long ago converted to Islam, and that the superstitions of the Eastern Christians (Greek Orthodox, Copts, Armenians, etc.) are in many ways what sustained them:

Save for a few years after the time of Constantine and a few years after
the First Crusade, they have been practically persecuted all the time.
At least they have been under heathen masters whose attitude towards
Christendom was hatred and whose type of government was despotism.
No man living in the West can form the faintest conception
of what it must have been to live in the very heart of the East
through the long and seemingly everlasting epoch of Moslem power.
A man in Jerusalem was in the centre of the Turkish Empire as a man
in Rome was in the centre of the Roman Empire. The imperial power
of Islam stretched away to the sunrise and the sunset; westward to
the mountains of Spain and eastward towards the wall of China.
It must have seemed as if the whole earth belonged to Mahomet to those
who in this rocky city renewed their hopeless witness to Christ.
What we have to ask ourselves is not whether we happen in
all respects to agree with them, but whether we in the same
condition should even have the courage to agree with ourselves.

G.K. Chesterton
The New Jerusalem (1920)
Chapter 4