10 Now first of all, before we show from these very texts, that He was subject to no infirmity of fear or sorrow on His own account, let us ask, “What can we find for Him to fear, that the dread of an unendurable pain should have seized Him?” The objects of His fear, which they allege, are, I suppose, suffering and death. Now I ask those who are of this opinion, Can we reasonably suppose that He feared death, Who drove away the terrors of death from His Apostles, exhorting them to the glory of martyrdom with the words, He that does not take his cross and follow after Me is not worth of Me; and, He that finds his life shall lose it, and he that has lost his life for My sake shall find it ? If to die for Him is life, what pain can we think He had to suffer in the mystery of death, Who rewards with life those who die for Him? Could death make Him fear what could be done to the body, when He exhorted the disciples, Fear not those which kill the body ?
Source: On the Trinity (New Advent)