In fact, it is doubtful whether Christendom has ever quite recovered form the mass-conversion of the fashionable classes inside Rome and of the barbaric races outside Rome. Those conversions prepared the way for the Church of the Middle Ages, but the forcibleness of the conversions also prepared the way for the Church of all the after ages. It is at least arguable that the Christian Church will have to return to a pre-Constantine state before she can properly recover the ground she too quickly won.
Her victories, among other disadvantages, produced in her children a great tendency to be aware of evil rather than of sin, meaning by evil the wickedness done by others, by sin the wickedness done by oneself. The actuality of evil does not altogether excuse the hectic and hysterical attention paid to it; especially to those who appear to be deriving benefit from it; especially to benefits which the Christian spectator strongly disapproves or strongly desires. Even contrition for sin is apt to encourage a not quite charitable wish that other people should exhibit a similar contrition.
-Charles Williams, The Descent of the Dove, p.86
Also, I’ve seen this sort of reasoning used as a stick to beat baby-baptisers with, but in fact I think it should probably be reserved for beating fans of conquest-evangelism.
I think he’s right here, though I’d never considered how this has shaped Christianity for the past 1600 years (and continues to shape it today). When the church in a place like China is pursecuted and driven underground, does that return it to this necessary pre-Constantinian state in some sense?