The first point which Celsus brings forward, in his desire to throw discredit upon Christianity, is, that the Christians entered into secret associations with each other contrary to law, saying, that “of associations some are public, and that these are in accordance with the laws; others, again, secret, and maintained in violation of the laws.” And his wish is to bring into disrepute what are termed the “love-feasts” of the Christians, as if they had their origin in the common danger, and were more binding than any oaths.
Since, then, he babbles about the public law, alleging that the associations of the Christians are in violation of it, we have to reply, that if a man were placed among Scythians, whose laws were unholy, and having no opportunity of escape, were compelled to live among them, such an one would with good reason, for the sake of the law of truth, which the Scythians would regard as wickedness, enter into associations contrary to their laws, with those like-minded with himself; so, if truth is to decide, the laws of the heathens which relate to images, and an atheistical polytheism, are “Scythian” laws, or more impious even than these, if there be any such.
It is not irrational, then, to form associations in opposition to existing laws, if done for the sake of the truth. For as those persons would do well who should enter into a secret association in order to put to death a tyrant who had seized upon the liberties of a state, so Christians also, when tyrannized over by him who is called the devil, and by falsehood, form leagues contrary to the laws of the devil, against his power, and for the safety of those others whom they may succeed in persuading to revolt from a government which is, as it were, “Scythian,” and despotic.
Source: Against Celsus (New Advent)