Here he only sets forth this advantage. Then, from verse 21, he begins the actual rebuke, as though saying: all this should indeed be so, but what are you yourselves like?
“And you are confident,” πέποιθάς τε. That is, you also trust, you think of yourself, you are persuaded about yourself, that you are this and that. No special distinction need be given to the words guide, light, instructor, and teacher. They may be understood as one thing, expressed in different ways, namely, what the possessor of truth becomes for those ignorant of it when he communicates it to them. Then truth itself teaches, instructs, enlightens, and guides. Like manna, it is suited to every kind of nourishment.
Yet one may also see in these words an indication of distinct forms of enlightenment by the truth. Infants are already ignorant of truth in themselves, for they have not yet grown to the use of reason that can know truth. The foolish, άφρονες, are not deprived of mind, but have not developed it. They are ignorant people who have not cared to enrich their reason with knowledge of the truth. They are the same as infants, not understanding the matter, but they are childish not by nature, but through their own fault. Those who are in darkness have eyes and do not see, because there is no light. The blind are surrounded by light and do not see, because they have no eyes.
It may also be taken this way. Infants are those beginning to learn and to know. The unreasonable know, but do not know how to act according to what they know. The first need teaching, and teachers, διδάσκαλοι, teach them. The second need practical instruction in how to act, and instructors, παιδευταί, train them. Thus one may see here two sides of teaching: the interpretation of truth and the training in how to live according to truth. The same may be seen in the last two terms. A candle is given to one who is in darkness, the light of knowledge. The blind man is taken by the hand and led, being told where to step. This indicates the manner of guidance in knowledge and in the training of life. The Jew could be all this for all nations, and indeed was so for proselytes.
Then, in the words, “having the form of knowledge and truth in the law,” by knowledge one may understand understanding, and by truth a life corresponding to that knowledge; see Photius in Oecumenius. For knowledge becomes real knowledge only when it enters into life and is carried out in deed. The Jew had both in the law. The written law communicated knowledge to him and showed how he ought to order his life. The form of both, the true form of what each ought to be, was impressed on the minds of the Jews through instruction in the law and study of it.
There is nothing blameworthy in all this. All this is as it ought to be. The Apostle does not reproach them for this. He sets it forth in order first to lay the foundation for the reproach. The reproach is only hinted at here in the words, “you are confident that you yourself are.” You think this of yourself. God taught through him, but he appropriated teaching to himself as though he were its source. Did not this self-conceit lead to disorder in life? And then did not disorder in life corrupt the teaching itself? For when someone’s life does not correspond to truth, his word is neither clear nor persuasive. Therefore the Jew, according to his appointment, thought that he was a guide and teacher. Yet in practice he had already ceased to be such when he ceased to live as he ought.
Chrysostom says: “Again he did not say, ‘You are a guide of the blind,’ but says, ‘Thinking yourself to be such, you boast in it.’” Photius in Oecumenius writes: “He appropriates to himself the form of knowledge and of the truth that is in the law who knows the law and lives according to it. He appropriates the form of knowledge when he knows, and the form of truth when he carries out in deed what he has known. For only he shows the knowledge in the law to be true who fulfills it in deed. Only such a man shows it to be faithful. But you, he says, regard yourself as an instructor, guide, and teacher, and not merely in some ordinary sense. You think you have the form of the knowledge in the law and of the truth in the law. Yet you live as one who has never heard the teaching of the law. Therefore, since you think you have the form of knowledge and truth, and think you are an instructor of the unreasonable, a guide, and a teacher, first teach yourself. When by deed you show that your teaching is true in you, then you will teach others also.” These words serve as a good transition to the rebuke that follows, namely, that they know but do not do.
THEOSIS