Orthodoxy does not have a history. It is true eternally. Heresy has a history, having arisen at particular times through particular teachers.
~ Eusebius of Caesarea
The age of the martyrs has a powerful attraction even to the casual reader; the age of the heresies leaves him bewildered and distressed. Yet the agents in both were discharging an equally necessary function. Both were upholding the truth of the gospel; the one against the power of the world, the other against the wisdom of the world. The martyrs had this advantage, that the force of their testimony was concentrated in one supreme moment, was expressed in one heroic act, which commands universal sympathy. The controversialists had to live through a protracted struggle and are judged by their utterances, and all their human weaknesses which the conflict remorselessly revealed.
~ Mandell Creighton, quoted by B. B. Warfield in Selected Shorter Writings, vol. 2, page 214