Origen — as excerpted in the Catena Aurea on Matthew 26:39-44

“Here it should be enquired, whether as all men’s flesh is weak, so all men’s spirit is willing, or whether only that of the saints; and whether in unbelievers the spirit is not also dull, as the flesh is weak. In another sense the flesh of those only is weak whose spirit is willing, and who with their willing spirit do mortify the deeds of the flesh. These then He would have watch and pray that they should not enter into temptation, for the more spiritual any one may be, the more careful should he be that his goodness should not suffer a great fall.”