Augustine of Hippo
Catena Aurea · Johannesevangelium 14
Let not your heart be troubled, neither let it be afraid. Ye have heard how I said unto you, I go away, and come again unto you. If ye loved me, ye would rejoice, because I said, I go unto the Father: for my Father is greater than I. And now I have told you before it come to pass, that, when it is come to pass, ye might believe. Hereafter I will not talk much with you: for the prince of this world cometh, and hath nothing in me. But that the world may know that I love the Father: and as the Father gave me commandment, even so I do. Arise, let us go hence.
(Tract. lxxix. 1) But is not the time for belief before a thing takes place? Is it not the praise of faith, that it believes what it does not see? according to what is said below to Thomas: Because thou hast seen, thou hast believed. He saw one thing, believed another: what he saw was man, what he believed was God. And if belief can be talked of with reference to things seen, as when we say that we believe our eyes; yet it is not mature faith, but is merely preparatory to our believing what we do not see. When it has come to pass; then He says, because after His death they would see Him alive again, and ascending to His Father; which sight would convince them that He was the Christ, the Son of God; able as He was to do so great a thing, and to foretell it. Which faith however would not be a new, but only an enlarged faith; or a faith which had failed at His death, and been renewed by His resurrection.