Think now what passion there was in primitive Christianity, without which it never would have come into the world: propose to one of those figures the question, “Dare a Christian tranquillize himself in this way?” “Abominable,” he would reply, “horrible, that a Christian, if only he might be allowed for himself to live as he would, that a Christian should tranquilly keep silent in the face of the fact that God every day is mocked by people pretending by millions to be Christians and worshiping Him by taking Him for a fool, that in the face of that he should keep silent, and not instantly—for the honor of God—venture sufferingly in among those millions, gladly suffering for the doctrine! For let us not forget that whereas in one sense Christianity is doubtless the most tolerant of all religions, inasmuch as most of all it abhors the use of physical power, it is in another sense the most intolerant, inasmuch as us true confessors recognize no limit with respect to compelling others by suffering themselves, compelling others by suffering their ill-treatment and persecution.
Søren Kierkegaard, Attack Upon “Christendom” pp 184-5.