Vs. 8, 9. These verses confirm the preceding declaration. The manifestation of the grace of God is the great end of redemption. This is plain, for salvation is entirely of grace. Ye are saved by grace; ye are saved by faith and not by works; and even faith is not of yourselves, it is the gift of God. We have then here a manifold assertion, affirmative and negative, of the gratuitous nature of salvation. It is not only said in general, ‘ye are saved by grace,’ but further that salvation is by faith, i. e. by simply receiving or apprehending the offered blessing. From the very nature of faith, as an act of assent and trust, it excludes the idea of merit. If by faith, it is of grace; if of works, it is of debt; as the apostle argues in Rom. 4:4, 5. Faith, therefore, is the mere causa apprehendens, the simple act of accepting, and not the ground on which salvation is bestowed. Not of works. The apostle says works, without qualification or limitation. It is not, therefore, ceremonial, as distinguished from good works; or legal, as distinguished from evangelical or gracious works; but works of all kinds as distinguished from faith, which are excluded. Salvation is in no sense, and in no degree, of works; for to him that worketh the reward is a matter of debt. But salvation is of grace and therefore not of works lest any man should boast. That the guilty should stand before God with self-complacency, and refer his salvation in any measure to his own merit, is so abhorrent to all right feeling that Paul assumes it (Rom. 4:2) as an intuitive truth, that no man can boast before God. And to all who have any proper sense of the heavens of God and of the evil of sin, it is an introduction and therefore a gratuitous salvation, a salvation which excludes with works all ground of boasting, is the only salvation suited to the relation of guilty men to God.
—Charles Hodge, A Commentary on the Epistle to the Ephesians (New York: Robert Carter and Brothers, 1858), 117–19.