If we are enjoined, then, to love our enemies, as I have remarked above, whom have we to hate? If injured, we are forbidden to retaliate, lest we become as bad ourselves: who can suffer injury at our hands? In regard to this, recall your own experiences. How often you inflict gross cruelties on Christians, partly because it is your own inclination, and partly in obedience to the laws! How often, too, the hostile mob, paying no regard to you, takes the law into its own hand, and assails us with stones and flames!
With the very frenzy of the Bacchanals, they do not even spare the Christian dead, but tear them, now sadly changed, no longer entire, from the rest of the tomb, from the asylum we might say of death, cutting them in pieces, rending them asunder. Yet, banded together as we are, ever so ready to sacrifice our lives, what single case of revenge for injury are you able to point to, though, if it were held right among us to repay evil by evil, a single night with a torch or two could achieve an ample vengeance?
But away with the idea of a sect divine avenging itself by human fires, or shrinking from the sufferings in which it is tried. If we desired, indeed, to act the part of open enemies, not merely of secret avengers, would there be any lacking in strength, whether of numbers or resources? The Moors, the Marcomanni, the Parthians themselves, or any single people, however great, inhabiting a distinct territory, and confined within its own boundaries, surpasses, forsooth, in numbers, one spread over all the world!
We are but of yesterday, and we have filled every place among you— cities, islands, fortresses, towns, market-places, the very camp, tribes, companies, palace, senate, forum—we have left nothing to you but the temples of your gods. For what wars should we not be fit, not eager, even with unequal forces, we who so willingly yield ourselves to the sword, if in our religion it were not counted better to be slain than to slay? Without arms even, and raising no insurrectionary banner, but simply in enmity to you, we could carry on the contest with you by an ill-willed severance alone.
For if such multitudes of men were to break away from you, and betake themselves to some remote corner of the world, why, the very loss of so many citizens, whatever sort they were, would cover the empire with shame; nay, in the very forsaking, vengeance would be inflicted. Why, you would be horror-struck at the solitude in which you would find yourselves, at such an all-prevailing silence, and that stupor as of a dead world. You would have to seek subjects to govern. You would have more enemies than citizens remaining.
For now it is the immense number of Christians which makes your enemies so few—almost all the inhabitants of your various cities being followers of Christ. Yet you choose to call us enemies of the human race, rather than of human error. Nay, who would deliver you from those secret foes, ever busy both destroying your souls and ruining your health? Who would save you, I mean, from the attacks of those spirits of evil, which without reward or hire we exorcise? This alone would be revenge enough for us, that you were henceforth left free to the possession of unclean spirits.
But instead of taking into account what is due to us for the important protection we afford you, and though we are not merely no trouble to you, but in fact necessary to your well-being, you prefer to hold us enemies, as indeed we are, yet not of man, but rather of his error.
Source: The Apology (New Advent)