For the Christians are distinguished from other men neither by country, nor language, nor the customs which they observe. For they neither inhabit cities of their own, nor employ a peculiar form of speech, nor lead a life which is marked out by any singularity. …They dwell in their own countries, but simply as sojourners. As citizens, they share in all things with others, and yet endure all things as if foreigners. Every foreign land is to them as their native country, and every land of their birth as a land of strangers.

Epistle to Diognetus 5.1–2, 5, mid-2nd century AD