Forbearing one another in love ... — The word rendered “endeavouring” is, in the original, a word expressing “earnestness” of thought and exertion to secure a thing not lightly obtained. (See 2 Timothy 4:9-21; Hebrews 4:11; 2 Peter 1:10.) It shows that St. Paul here passes from the negative aspects of love, summed up in forbearance, to the more positive and energetic enthusiasm for unity and peace. Love is in both aspects, the “uniting bond” of peace. In the parallel passage of Colossians 3:14, it is “put on over” all else, and is the uniting “bond of perfectness.” In the celebrated thirteenth chapter of the First Epistle to Corinthians (Ephesians 4:4-7) it is made to include “long-suffering” and “kindness,” and all forms of humility and gentleness. But, if it be real, it must necessarily pass into active energy; if it is to win the final beatitude of “blessing to the peacemakers,” it must “labour for peace,” and “follow after the things which make for peace” (Psalms 120:7; Romans 14:19).
The unity of the Spirit is certainly the unity given by the indwelling of the Holy Ghost. This we cannot create, for it is the gift of God; but we can “keep” it: that is, cherish it, guard it, and make it effectual by love; and all experience proves that, if we would so keep it, we need the positive earnestness of exertion against evils without and within.