Augustine of Hippo

"The Life was manifested." Christ therefore is "the word of life." And whereby manifested? For it was "from the beginning," only not manifested to men: but it was manifested to angels, who saw it and fed on it as their bread. But what saith the Scripture? "Man did eat angels' bread." Well then "the Life was manifested" in the flesh; because it exhibited in manifestation, that that which can be seen by the heart only, should be seen by the eyes also, that it might heal the hearts. For only by the heart is the Word seen: but the flesh is seen by the bodily eyes also. We had wherewith to see the flesh, but had not wherewith to see the Word: "the Word was made flesh," which we might see, that so that in us might be healed wherewith we might see the Word.

"We have seen and are witnesses." Perhaps some of the brethren who are not acquainted with the Greek do not know what the word "witnesses" is in Greek: and yet it is a term much used by all, and had in religious reverence; for what in our tongue we call "witnesses," in Greek are "martyrs." Now where is the man that has not heard of martyrs, or where the Christian in whose mouth the name of martyrs dwelleth not every day? For it was for bearing witness of that which they had seen, and bearing witness of that which they had heard from them who had seen, that, while their testimony itself displeased the men against whom it was delivered, the martyrs suffered all that they did suffer. The martyrs are God's witnesses.