John Chrysostom

But since some maintain that the expression, "when one shall turn to the Lord," is spoken of the Son, in contradiction to what is quite acknowledged; let us examine the point more accurately, having first stated the ground on which they think to establish this. What then is this? Like, saith one, as it is said, "God is a Spirit;" so also here, 'The Lord is a Spirit.' But he did not say, 'The Lord is a Spirit,' but, "The Spirit is the Lord." And there is a great difference between this construction and that. For when he is desirous of speaking so as you say, he does not join the article to the predicate. And besides, let us review all his discourse from the first, of whom hath he spoken? for instance, when he said, "The letter killeth, but the Spirit giveth life:" and again, "Written not with ink, but with the Spirit of the living God;" was he speaking of God, or of the Spirit? It is very plain that it was of the Spirit; for unto It he was calling them from the letter. For lest any, hearing of the Spirit, and then reflecting that Moses turned unto the Lord, but himself unto the Spirit, should think himself to have the worse, to correct such a suspicion as this, he says, "Now the Spirit Is the Lord." This too is Lord, he says. And that you may know that he is speaking of the Paraclete, he added, "And where the Spirit of the Lord is, there is liberty."

For surely you will not assert, that he says, 'And where the Lord of the Lord is.' "Liberty," he said, with reference to the former bondage.