G.k. Chesterton said this quote
“ I should say that there ought to be no war except religious war. If war is irreligious, it is immoral. No man ought ever to fight at all unless he is prepared to put his quarrel before that invisible Court of Arbitration with which all religion is concerned. Unless he thinks he is vitally, eternally, cosmically in the right, he is wrong to fire off a pocket-pistol. ”