30 They err greatly, therefore, who lose faith during the storm, wishing for themselves and the Church a permanent state of perfect tranquillity, universal prosperity, and practical, unanimous and uncontested recognition of her sacred authority. But the error is worse when men deceive themselves with the idea of gaining an ephemeral peace by cloaking the rights and interests of the Church, by sacrificing them to private interests, by minimizing them unjustly, by truckling to the world, "the whole of which is seated in wickedness" (I Ioan . v. 19) on the pretext of reconciling the followers of novelties and bringing them back to the Church, as though any composition were possible between light and darkness, between Christ and Belial. This hallucination is as old as the world, but it is always modern and always present in the world so long as there are soldiers who are timid or treacherous, and at the first onset ready to throw down their arms or open negotiations with the enemy, who is the irreconcilable enemy of God and man.
Source: Communium Rerum (Vatican.va)