5 Here a question meets us: for it is not this or that man, or you or I that come in question—for if I have asked any thing of God and receive it not, any person may easily say of me, “He has not charity:” and of any man soever of this present time, this may easily be said; and let any think what he will, a man of man:— not we, but those come more in question, those men of whom it is on all hands known that they were saints when they wrote, and that they are now with God.
Where is the man that has charity, if Paul had it not, who said, “Our mouth is open unto you, O you Corinthians, our heart is enlarged; you are not straitened in us:” who said, “I will myself be spent for your souls:” and so great grace was in him, that it was manifested that he had charity. And yet we find that he asked and did not receive. What say we, brethren? It is a question: look attentively to God: it is a great question, this also. Just as, where it was said of sin, “He that is born of God sins not:” we found this sin to be the violating of charity, and that this was the thing strictly intended in that place: so too we ask now what it is that he would say.
For if you look but to the words, it seems plain: if you take the examples into the account, it is obscure. Than the words here nothing can be plainer. “And whatsoever we ask, we shall receive of Him, because we keep His commandments, and do those things that are pleasing in His sight.” “Whatsoever we ask,” says he, “we shall receive of Him.” He has put us sorely to straits. In the other place also he would put us to straits, if he meant all sin: but then we found room to expound it in this, that he meant it of a certain sin, not of all sin; howbeit of a sin which “whosoever is born of God commits not:” and we found that this same sin is none other than the violation of charity.
We have also a manifest example from the Gospel, when the Lord says, “If I had not come, they had not had sin.” How? Were the Jews innocent when He came to them, because He so speaks? Then if He had not come, would they have had no sin? Then did the Physician's presence make one sick, not take away the fever? What madman even would say this? He came not but to cure and heal the sick. Therefore when He said, “If I had not come, they had not had sin,” what would He have to be understood, but a certain sin in particular?
For there was a sin which the Jews would not have had. What sin? That they believed not on Him, that when he had come they despised Him. As then He there said “sin,” and it does not follow that we are to understand all sin, but a certain sin: so here also not all sin, lest it be contrary to that place where he says, “If we say that we have no sin, we deceive ourselves, and the truth is not in us:” but a certain sin in particular, that is, the violation of charity. But in this place he has bound us more tightly: “If we shall ask,” he has said, “if our heart accuse us not, and tell us in answer, in the sight of God, that true love is in us;” “Whatsoever we ask, we shall receive of Him.”
Source: Homilies on the First Epistle of John (New Advent)