More permissable to be killed than to kill.
“We [the Christians] started yesterday and already we have filled the world and everything that belongs to you — the cities, apartment houses, fortresses, towns, market places, the camps themselves, your tribes, town councils, the imperial palace, the Senate, the Forum. The only thing we have left to you are the temples. We can count your armies; there is a greater number of Christians in one province! What kind of war would we, who willingly submit to the sword, not be ready or eager for despite our inferior numbers if it were not for the fact that according to our doctrine it is more permissible to be killed than to kill.” – Tertullian, Apology, 37:4