Christianity is an apologetic religion. Not only now, in the second period of the Reformation epoch, from the close of the seventeenth century to this day, apology has been, by force of circumstances, a prominent action of the religion toward the world. In the primitive Church history, too, there was a “period of apologetics,” which in other respects was the most glorious period in all that history, the first heroic age of confession and of martyrdom for truth. And this, occasioned by outward conditions of the time, was in accordance with the distinctive genius of the system, as appearing in scriptural precedent and rule.
Christianity is the apologetic religion. No other religion has ever seriously set itself to the endeavour to subdue a hostile world by apology (from logos, “reason,” or “reason,” ratio vel oratio, 1 Pet. iii. 15), to reason the sinful world out of worldliness into godliness. The aspect of the new religion thus appearing toward the freedom of the human soul, in addressing itself to the reason in order to reach the man in his conscience and his heart, struck intelligent heathens as a presumptive evidence of truth and divinity, since reason is “the door” (John x. 1, etc.)—the lawful way—of seeking to win and to control the manhood.
James MacGregor, The Apology of the Christian Religion (Edinburgh: T. & T. Clark, 1891), p. 9.