The unity of the Spirit - A united spirit, or oneness of spirit. This does not refer to the fact that there is one Holy Spirit; but it refers to unity of affection, of confidence, of love. It means that Christians should be united in temper and affection, and not be split up into factions and parties. It may be implied here, as is undoubtedly true, that such a unity would be produced only by the Holy Spirit; and that, as there was but one Spirit which had acted on their hearts to renew them, they ought to evince the same feelings and views. There was occasion among the Ephesians for this exhortation; for they were composed of Jews and Gentiles, and there might be danger of divisions and strifes, as there had been in other churches. There is “always” occasion for such an exhortation; for:
(1) “unity” of feeling is eminently desirable to honor the gospel (see the notes on John 17:21); and,
(2) There is always danger of discord where people are brought together in one society. There are so many different tastes and habits; there is such a variety of intellect and feeling; the modes of education have been so various, and the temperament may be so different, that there is constant danger of division. Hence, the subject is so often dwelt on in the Scriptures (see the notes on 1 Cor. 2ff), and hence, there is so much need of caution and of care in the churches.
In the bond of peace - This was to be by the cultivation of that peaceful temper which binds all together. The American Indians usually spoke of peace as a “chain of friendship” which was to be kept bright, The meaning here is, that they should be bound or united together in the sentiments and affections of peace. It is not mere “external” unity; it is not a mere unity of creed; it is not a mere unity in the forms of public worship; it is such as the Holy Spirit produces in the hearts of Christians, when it fills them all with the same love, and joy, and peace in believing. The following verses contain the reasons for this.