3.  While the Christian Fathers and the missionaries differed in their estimates of heathenism, and in their methods of dealing with it, one thing was recognized by all whom we designate as the great leaders, namely, the imperative necessity of a thorough knowledge of it.  They understood both the low superstition of the masses and the loftier teaching of the philosophers.  On the other hand, they had the same estimate of the incomparable Gospel of Christ that we have; they realized that it was the wisdom of God and the power of God unto salvation as clearly as the best of us, but they did not claim that it was to be preached blindly and without adaptation.  The verities of the New Testament teachings, the transforming power of the Holy Ghost, the necessity for a new birth and for the preternatural influence of grace, both in regeneration and in sanctification, were as strongly maintained as they have ever been in any age of the Church; but the Fathers were careful to know whether they were casting the good seed upon stony places, or into good ground where it would spring up and bear fruit.  The liberal education of that day was, in fact, an education along the old lines of heathen philosophy, poetry, history, and rhetoric; and a broad training was valued as highly as it has been in any subsequent period.  It was thoroughly understood that disciplined intellect, other things being equal, may expect a degree of influence which can never fall to the lot of ignorance, however sanctified its spirit.  There has never been a stronger type of men than the Christian Fathers.  They were learned men, for the age in which they lived, and their learning had special adaptations to the work assigned them.  Many of them, like Cyprian, Clement, Hilary, Martin of Tours, had been born and educated in heathenism; while others, like Basil, Gregory, Origen, Athanasius, Jerome, and Augustine, though born under Gospel influences, studied heathen philosophy and poetry at the instance of their Christian parents.

4.  Some of the leaders familiarized themselves with the speculations of the day, not merely for the sake of a wider range of knowledge, but that they might the more successfully refute the assailants of the faith, many of whom were men of great power.  They were fully aware that it behooved them to know their ground, for their opponents studied the points of comparison carefully.  The infidel Celsus studied Christianity and its relation to the Old Testament histories and prophecies, and he armed himself with equal assiduity with all the choicest weapons drawn from Greek philosophy.  How was such a man to be met?  His able attack on Christianity remained fifty years unanswered.  To reply adequately was not an easy task.  Doubtless there were many, then as now, who thought that the most comfortable way of dealing with such things was to let them alone.  But a wiser policy prevailed.  Origen was requested to prepare an answer, and, although such work was not congenial to him, he did so because he felt that the cause of the truth demanded it.  His reply outlived the attack which it was designed to meet, and in all subsequent ages it has been a bulwark of defence.[32]