On the coming of the Son of God, from the Letter to Diognetus—
“For who that is rightly taught and begotten by the loving Word, would not seek to learn accurately the things which have been clearly shown by the Word to His disciples, to whom the Word being manifested has revealed them, speaking plainly [to them], not understood indeed by the unbelieving, but conversing with the disciples, who, being esteemed faithful by Him, acquired a knowledge of the mysteries of the Father? For which reason He sent the Word, that He might be manifested to the world; and He, being despised by the people [of the Jews], was, when preached by the Apostles, believed on by the Gentiles.
“This is He who was from the beginning, who appeared as if new, and was found old, and yet who is ever born afresh in the hearts of the saints. This is He who, being from everlasting, is today called the Son; through whom the Church is enriched, and grace, widely spread, increases in the saints, furnishing understanding, revealing mysteries, announcing times, rejoicing over the faithful, giving to those that seek, by whom the limits of faith are not broken through, nor the boundaries set by the fathers passed over. Then the fear of the law is chanted, and the grace of the prophets is known, and the faith of the gospels is established, and the tradition of the Apostles is preserved, and the grace of the Church exults—by which grace if you grieve not, you shall know those things which the Word teaches, by whom He wills, and when He pleases.”