Unity is not a feeling, but a fact. It was central in the prayer of our Lord in John 17. His desire was that believers should be “one” (Jn. 17:21).
Paul picks up the theme in Ephesians 4 where we are given the fullest explanation of unity in the epistles. He describes unity as “the unity of the Spirit” (Eph. 4:3). It is a significant theme in the New Testament.
Unity among believers is an expression of the work and character of God (Jn. 17:11, 21). The Lord Jesus emphasized in His prayer the oneness of the Father and the Son, and in a startling connection links this to believers in Christ. The relation of the two unities would be suspect if He had not said it. God is one. We are one. This was His prayer.
This unity is a witness to the world. “…that the world may believe that Thou hast sent Me” (Jn. 17:21). Some may conclude that the power of the witness is simply everybody “getting along.” That conclusion is questionable as evidenced by the fact that other gatherings of people can demonstrate “getting along” apart from any Christian testimony. There must be more to this witness.
The truth is the essence of “the unity of the Spirit” (Eph. 4:13-15). The Lord Jesus said in John 16:13 that “…when He, the Spirit of truth, is come, He will guide you into all truth…” This is the consistent message from the early apostles through the early church age as seen in all the epistles. Anything that detracts from the truth about the person and work of the Lord Jesus is an enemy of unity.
Unity grows in diversity. Again consulting Ephesians 4 we notice the various diversities contributing to unity. Diversity among men is given as a foundation to the church: apostles and prophets, evangelists, shepherds, and teachers (v. 10), as well as diversity among all believers. Notice Paul’s reference to “we” and “us.” The force of his argument is a growing body each contributing to growth and development in submission to the risen Head.
The object of unity is maturity. The language of the apostle is plain. His words in Ephesians 4:12-16 are all expressions of growing, increasing, edifying, and maturing. Maturing in the knowledge of Christ is the unity of the Spirit. This prevents us from being unstable, “tossed to and fro, and carried about with every wind of doctrine…” (Eph. 4:14).
The opposition to unity is division. The apostle spoke to the Corinthians about their division. In their case it was the carnality of being occupied with personalities (1 Cor. 1:12-13). The Romans were warned against those who cause divisions, thus exposing their ulterior motives. They are to be avoided (Rom. 16:17-18). To Titus, the language is stronger. Here the heretic (divider) is to be rejected completely (Titus 3:10). But to the Corinthians, Paul points out that dividers in the assembly, although causing great grief, also give opportunity to confirm the truth. In 1 Corinthians 11:19, he explains that sometimes God allows division in order “that they which are approved may be made manifest among you.”
Unity is advanced by speaking “the truth in love.” We are exhorted to not only grow in the truth, but cultivate the ability to speak the truth in love. Immaturity and lack of knowledge on the part of new believers can provoke irritation and cause us to act immaturely as well. Speaking the truth in love towards one another is a powerful force against error and promotes growth in fellow-believers. Evil is powerless against love; it never fails.
Unity honors the Lord Jesus and is in harmony with His will. Believers who “keep the unity of the Spirit in the bond of peace” are practically living out the will of the Lord. His interest is in His people knowing more of Him and growing together in harmony around the central truths about Him.
No wonder we are exhorted to “keep the unity,” that is, to watch over and preserve it. Only the Spirit can make this unity, but it is possible that we can damage it. Unity never compromises the truth as it grows in loving hearts. Watch it!