Charles Hodge on Ephesians 4:17

V. 17. The apostle, having in the preceding section taught that Christ had destined his church to perfect conformity to himself, and made provision for that end, as a natural consequence, solemnly enjoins on those who profess to be Christians to live in accordance with this high vocation. "This therefore I say and testify in the Lord, that he henceforth walk not as the other Gentiles walk, in the vanity of their mind." To testify, in this case, is solemnly to enjoin, as a man does who calls upon God to bear witness to the truth and importance of what he says. Μαρτυρέω is to act as a witness, and μαρτύρομαι to invoke as a witness. The latter is the word here used. In the Lord, means in communion with the Lord. Paul speaks as one who had access to the mind of Christ, knew his will, and could therefore speak in his name. The exhortation is, not to walk as the Gentiles do. To walk, in Scripture language, includes all the manifestations of life, inward and outward, seen and unseen. It does not express merely the outward, visible deportment. Men are said to walk with God, which refers to the secret fellowship of the soul with its Maker, more than to the outward life. So here the walk, which the apostle enjoins us to avoid, is not only the visible deportment characteristic of the Gentiles, but also the inward life of which the outward deportment is the manifestation.

They walk "in the vanity of their mind." The language of the New Testament being the language of Jews, is more or less modified by Hebrew usage. And the usage of Hebrew words is of course modified by the philosophy and theology of the people who employed them. There are two principles which have had an obvious influence on the meaning of a large class of Hebrew words, and therefore on the meaning of the Greek terms which answer to them. The one is the unity of the soul which forbids any such marked distinction between its cognitive and emotional faculties, i. e. between the understanding and the heart, as is assumed in our philosophy, and therefore is impressed on our language. In Hebrew the same word designates what we commonly distinguish as separate faculties. The Scriptures speak of an "understanding heart," and of "the desires of the understanding," as well as of "the thoughts of the heart." They recognize that there is an element of feeling in our cognitions and an element of intelligence in our feelings. The idea that the heart may be depraved and the intellect unaffected is, according to the anthropology of the Bible, as incongruous, as that one part of the soul should be happy and another miserable, one faculty saved and another lost.

Another principle nearly allied to the former is the moral and spiritual excellence of truth. Truth is not merely speculative, the object of cognition. It has moral beauty. In scriptural language, therefore, knowledge includes love; wisdom includes goodness; folly includes sin; the wise are holy, fools are wicked. Truth and holiness are united as light and heat in the same ray. There cannot be the one without the other. To know God is eternal life; to be without the knowledge of God is to be utterly depraved. Saints are the children of light; the wicked are the children of darkness. To be enlightened is to be renewed; to be blinded is to be reprobated. Such is the constant representation of Scripture.

The νοῦς, mind, therefore, in the passage before us, does not refer to the intellect to the exclusion of the feelings, nor to the feelings to the exclusion of the intellect. It includes both; the reason, the understanding, the conscience, the affections are all comprehended by the term. Sometimes one and sometimes another of these modes of spiritual activity is specially referred to, but in the present case the whole soul is intended. The word ματαιότης, vanity, according to the scriptural usage just referred to, includes moral as well as intellectual worthlessness, or fatuity. It is of all that is comprehended under the word νοῦς, the understanding and the heart, that this vanity is predicated. Every thing included in the following verses respecting the blindness and depravity of the heathen is therefore comprehended in the word vanity.