Basil of Caesarea asked the title's question in a.d. 374 amidst theological battle, defending the doctrine of the Holy Spirit's person and nature as true God. He described the struggle as similar to naval warfare amongst those who are more intent on promoting themselves than the cause for which they are united. One cannot help but feel that the 21st-century church is falling victim to a similar malady as the Day of the Lord draws ever closer.
Turn now I beg you from this figurative description to the unhappy reality. Did it not at one time appear that the Arian schism, after its separation into a sect opposed to the Church of God, stood itself alone in hostile array? But when the attitude of our foes against us was changed from one of long standing and bitter strife to one of open warfare, then, as is well known, the war was split up in more ways than I can tell into many subdivisions, so that all men were stirred to a state of inveterate hatred alike by common party spirit and individual suspicion. But what storm at sea was ever so fierce and wild as this tempest of the Churches? In it every landmark of the Fathers has been moved; every foundation, every bulwark of opinion has been shaken: everything buoyed up on the unsound is dashed about and shaken down. We attack one another. We are overthrown by one another. If our enemy is not the first to strike us, we are wounded by the comrade at our side. If an enemy combatant is stricken and falls, his fellow soldier tramples him down. There is at least this bond of union between us that we hate our common foes, but no sooner have the enemy gone by than we find enemies in one another. And who could make a complete list of all the wrecks? Some have gone to the bottom on the attack of the enemy, some through the unsuspected treachery of their allies, some from the blundering of their own officers. We see, as it were, whole churches, crews and all, dashed and shattered upon the sunken reefs of disingenuous heresy, while others of the enemies of the Spirit of Salvation have seized the helm and made shipwreck of the faith. And then the disturbances wrought by the princes of the world have caused the downfall of the people with a violence unmatched by that of hurricane or whirlwind. The luminaries of the world, which God set to give light to the souls of the people, have been driven from their homes, and a darkness verily gloomy and disheartening has settled on the Churches. The terror of universal ruin is already imminent, and yet their mutual rivalry is so unbounded as to blunt all sense of danger. Individual hatred is of more importance than the general and common warfare, for men by whom the immediate gratification of ambition is esteemed more highly than the rewards that await us in a time to come, prefer the glory of getting the better of their opponents to securing the common welfare of mankind.
So all men alike, each as best he can, lift the hand of murder against one another. Harsh rises the cry of the combatants encountering one another in dispute; already all the Church is almost full of the inarticulate screams, the unintelligible noises, rising from the ceaseless agitations that divert the right rule of the doctrine of true religion, now in the direction of excess, now in that of defect. On the one hand are they who confound the Persons and are carried away into Judaism; on the other hand are they that, through the opposition of the natures, pass into heathenism. Between these opposite parties inspired Scripture is powerless to mediate; the traditions of the apostles cannot suggest terms of arbitration. Plain speaking is fatal to friendship, and disagreement in opinion all the ground that is wanted for a quarrel. No oaths of confederacy are so efficacious in keeping men true to sedition as their likeness in error. Every one is a theologian though he have his soul branded with more spots than can be counted. The result is that innovators find a plentiful supply of men ripe for faction, while self-appointed scions of the house of place-hunters reject the government of the Holy Spirit and divide the chief dignities of the Churches. The institutions of the Gospel have now everywhere been thrown into confusion by want of discipline; there is an indescribable pushing for the chief places while every self-advertiser tries to force himself into high office. The result of this lust for ordering is that our people are in a state of wild confusion for lack of being ordered; the exhortations of those in authority are rendered wholly purposeless and void, because there is not a man but, out of his ignorant impudence, thinks that it is just as much his duty to give orders to other people, as it is to obey anyone else.
Basil of Caesarea, On the Holy Spirit, 30.77