Texts Explained; Twelfthly, Matthew 26:39; John 12:27, etc. Arianinferences are against the Regula Fidei, as before. He wept and the like, as man. Other texts prove Him God. God could not fear. He feared because His flesh feared
57 And as to His saying, 'If it be possible, let the cup pass,' observe how, though He thus spoke, He rebuked Peter, saying, 'Thou savourest not the things that be of God, but those that be of men.' For He willed what He deprecated, for therefore had He come; but His was the willing (for for it He came), but the terror belonged to the flesh. Wherefore as man He utters this speech also, and yet both were said by the Same, to show that He was God, willing in Himself, but when He had become man, having a flesh that was in terror. For the sake of this flesh He combined His own will with human weakness, that destroying this affection He might in turn make man undaunted in face of death. Behold then a thing strange indeed! He to whom Christ's enemies impute words of terror, He by that so-called tenor renders men undaunted and fearless. And so the Blessed Apostles after Him from such words of His conceived so great a contempt of death, as not even to care for those who questioned them, but to answer, 'We ought to obey God rather than men.' And the other Holy Martyrs were so bold, as to think that they were rather passing to life than undergoing death. Is it not extravagant then, to admire the courage of the servants of the Word, yet to say that the Word Himself was in terror, through whom they despised death? But from that most enduring purpose and courage of the Holy Martyrs is shown, that the Godhead was not in terror, but the Saviour took away our terror. For as He abolished death by death, and by human means all human evils, so by this so-called terror did He remove our terror, and brought about that never more should men fear death. His word and deed go together. For human were the sayings, 'Let the cup pass,' and 'Why have You forsaken Me?' and divine the act whereby the Same did cause the sun to fail and the dead to rise. Again He said humanly, 'Now is My soul troubled;' and He said divinely, 'I have power to lay down My life, and power to take it again. ' For to be troubled was proper to the flesh, and to have power to lay down His life and take it again, when He will, was no property of men but of the Word's power. For man dies, not by his own power, but by necessity of nature and against his will; but the Lord, being Himself immortal, but having a mortal flesh, had power, as God, to become separate from the body and to take it again, when He would. Concerning this too speaks David in the Psalm, 'You shall not leave My soul in hades, neither shall Thou suffer Your Holy One to see corruption. ' For it beseemed that the flesh, corruptible as it was, should no longer after its own nature remain mortal, but because of the Word who had put it on, should abide incorruptible. For as He, having come in our body, was conformed to our condition, so we, receiving Him, partake of the immortality that is from Him.
58. Idle then is the excuse for stumbling, and petty the notions concerning the Word, of these Ario-maniacs, because it is written, 'He was troubled,' and 'He wept.' For they seem not even to have human feeling, if they are thus ignorant of man's nature and properties; which do but make it the greater wonder, that the Word should be in such a suffering flesh, and neither prevented those who were conspiring against Him, nor took vengeance of those who were putting Him to death, though He was able, He who hindered some from dying, and raised others from the dead. And He let His own body suffer, for therefore did He come, as I said before, that in the flesh He might suffer, and thenceforth the flesh might be made impassible and immortal, and that, as we have many times said, contumely and other troubles might determine upon Him and come short of others after Him, being by Him annulled utterly; and that henceforth men might for ever abide incorruptible, as a temple of the Word. Had Christ's enemies thus dwelt on these thoughts, and recognised the ecclesiastical scope as an anchor for the faith, they would not have made shipwreck of the faith, nor been so shameless as to resist those who would fain recover them from their fall, and to deem those as enemies who are admonishing them to be religious.
Source: Four Discourses Against the Arians (New Advent)