After the sack of Rome by the Goths, Augustine and his Christian contemporaries faced attacks from an entrenched pagan culture that blamed Christian practice for its troubles. Then as today, it’s easy to succumb to anger and defensiveness when facing such assaults, particularly in a time of cultural decline and civil tension. But Augustine urged his fellow believers not to forget, even as they vigorously answered the attacks of their enemies, that we are citizens of a pilgrim city, and the battle lines are not so cleanly drawn:
Let these and similar answers (if any fuller and fitter answers can be found) be given to their enemies by the redeemed family of the Lord Christ, and by the pilgrim city of King Christ. But let this city bear in mind, that among her enemies lie hid those who are destined to be fellow-citizens, that she may not think it a fruitless labour to bear what they inflict as enemies until they become confessors of the faith. So, too, as long as she is a stranger in the world, the city of God has in her communion, and bound to her by the sacraments, some who shall not eternally dwell in the lot of the saints. Of these, some are not now recognized; other declare themselves, and do not hesitate to make common cause with our enemies in murmuring against God, whose sacramental badge they wear. These men you may to-day see thronging the churches with us, to-morrow crowding the theaters with the godless. But we have the less reason to despair of the reclamation even of such persons, if among our most declared enemies there are now some, unknown to themselves, who are destined to become our friends. In truth, these two cities are entangled together in this world, and intermixed until the last judgment effect their separation.
City of God, Book 1.