14 Oh! That it were possible that I could perform good works as your substitute, and that you could receive the rewards of those works! Then I would not give you so much trouble. But how can I do this? The thing is impossible; for to every man will He render according to his own works. Wherefore as a mother, when she beholds her son in a fever, while she witnesses his sufferings from choking and inflammation, frequently bewails him, and says to him, “O my son, would that I could sustain your fever, and draw off its flame upon myself!” so now I say, Oh!
That by labouring as your substitute, I could do good works for you all! But no, this is not to be done. But of his own doings must each man give the account, and one cannot see one person suffer punishment in the room of another. For this reason I am pained and mourn, that on That Day, when you are called to judgment, I shall not be able to assist you, since, to say the truth, no such confidence of speech with God belongs to me. But even if I had much confidence, I am not holier than Moses, or more righteous than Samuel; of whom it is said, that though they had attained to so great virtue, they could not in any way avail to assist the Jews; inasmuch as that people had given themselves over to excessive negligence. Since, then, from our own works we shall be punished or saved; let us endeavour, I beseech you, in conjunction with all the other precepts, to fulfill this one; that, finally departing this life with a favourable hope, we may obtain those good things which are promised, through the grace and lovingkindness of our Lord Jesus Christ, through Whom and with Whom, to the Father, with the Holy Ghost, be glory both now and ever, world without end. Amen.
Source: Homilies on the Statues (New Advent)