“Endeavouring to keep the unity of the Spirit in the bond of peace” (Eph. 4:3). Blessed peace! Peace with God. Peace wrought by the sacrifice of Jesus Christ on the cross, through which Christ bore the wrath of God against all our sins—original and actual sins—and imputed to us perfect righteousness. Having established peace with God, Christ joins us by his Spirit into saving fellowship with himself. One by one, the Spirit draws all of God’s people into one body in Christ. That body is united as a human body is joined together. A human body has many members that support each other and without which the other members cannot function. Those members are united by joints, tendons, bones, and tissue. All the members of Christ’s body serve Christ their head. As the head of his body, Christ is the legal representative of all his people. Furthermore, that Christ is our head means that he takes us to be his own and gives to us all the blessings of salvation and of covenant fellowship with God. 

Believers in the church can be at peace with each other because they experience peace with God. Peace in the church is demonstrated in the church’s unity. That unity is “of the Spirit.” The unity of the Spirit is the unity of God himself in his own divine being, shared with his people in Jesus Christ. Only the Spirit can produce this unity. The natural man is at enmity against unity, just as he is at enmity with all things that are of the Spirit (1 Cor. 2:14). Man often stakes his claim on peace and unity. Man boasts of pursuing peace with his neighbor, even with his enemies. Man will even suffer great expense for the sake of what he calls “peace.” However, this is no peace at all. At best, man’s peace is an expression of tolerance. Peace for the natural man is inclusive: this false peace accepts everyone and everything and seeks never to offend anybody. Wretched peace! This is not the peace that is wrought by the Spirit of God.

Being of the Spirit, this unity is wholly spiritual. The spirituality of a church is expressed in her interest in spiritual things, including the defense of the truth of the sacred scriptures concerning her unity in Christ, godly marriages, the rearing of covenant seed, the support of the gospel ministry, and other like things. Being spiritual, this unity of the Spirit is not carnal. Unity and peace are not maintained in the church because everyone has similar likes and dislikes. Unity in the church is not maintained because her members only speak soft words with each other. Unity in a denomination of churches is not maintained because there are no admonitions, no warnings, and no rebukes found in her pulpits, consistory rooms, classes, and synods. God’s judgment of that church or denomination that prides herself in such “peace” is this:

11. They have healed the hurt of the daughter of my people slightly, saying, Peace, peace; when there is no peace. 
12. Were they ashamed when they had committed abomination? Nay, they were not at all ashamed, neither could they blush: therefore shall they fall among them that fall: in the time of their visitation they shall be cast down, saith the Lord.” (Jer. 8:11–12)

As believers—indeed, as Reformed Protestant believers—we are called of God to endeavor to keep the unity of the Spirit in the bond of peace. This does not mean that we maintain this unity among ourselves by our own strength and our own zeal for God and even for spiritual things. Rather, we are called to keep watch over the unity that we have with one another and to ward off any assaults against that unity.

Endeavoring to keep the unity of the Spirit means that we remain on our guard against false doctrines and heresies that easily creep into the church by hirelings who are not sent by the Lord but come with their own agendas, new ways of interpreting scripture, eloquence of speech, and smooth craftiness. That is, men who seek to create factions and divisions in the church by means of false doctrine, however subtle that false doctrine might present itself in our midst. Endeavoring to keep the unity of the Spirit involves calling sin and false doctrine out for what they truly are. No excuses, no minimization, and certainly no toleration.

Endeavoring to keep the unity of the Spirit is treating each member of the body of Christ in love: forbearing with one another, exercising lowliness of mind, and caring for one another in all things physical and spiritual. Furthermore, endeavoring to keep the unity of the Spirit means that we receive into our fellowship those whom God has given eyes to see the glorious truths that all of God’s people confess concerning the revelation of himself in Jesus Christ.

What, then, threatens our unity as individuals and as churches? It is my conviction that some of us have become entirely too comfortable in our dealings with those within our own immediate families and former friend groups, many of whom remain in the Protestant Reformed Churches (PRC). I am also guilty of this sin. After we have brought to light the issues within the PRC to our Protestant Reformed family members and friends once, twice, even multiple times, to the point where we have nearly run out of words to say, is it then lawful for us to silence the truth for the sake of some outward, carnal, and even superficial relationships? What is the heart of all godly relationships? Unity in Christ. Unity that is spiritual. Unity that can speak freely concerning those things that are of real interest to us—or at least they should be—including the truth of God’s unconditional covenant, the gracious experience of salvation in Christ, the sufficiency of Christ’s cross, and the power of the gospel.

I believe that a question we all need to ask ourselves is this: What draws me to keep this relationship? If it is not because we are like-minded and have fellowship in Christ, then it is carnal. Is it endeavoring to keep the unity of the Spirit whenever we—for the sake of family and close friends—come to all the family outings and social gatherings and accept every invitation to visit? Those who remain in the PRC bear witness by their membership that they concur with the promotion of false doctrine and the killing of God’s prophets. This is true of the most outspoken minister down to the family member or friend who would like nothing more than to fellowship with us, just not to speak about the controversy or the truth or the errors within his or her denomination.

And we bear witness, too, as those who have come out of that apostatizing denomination, of Christ. His name was on our lips whenever we separated from the apostatizing church. We confess by our membership in the Reformed Protestant Churches that we reject the false doctrine upheld in the PRC and abhor their murderous abuse of God’s prophets. What is our witness to those who remain in the PRC if any of us compromise the truth, setting it aside for the sake of a few passing moments of fellowship? Was Christ not displaced in the PRC? Why, then, did we ever need to separate and form the church anew? Why start our own Christian schools? Fundamentally, we must ask ourselves this sobering question: Does the truth mean more to me than anything? In other words: What am I willing to give up for the sake of the truth and out of love for those who cannot yet see the departure of their churches?

We should not be surprised if endeavoring to keep the unity of the Spirit forces us to cut off fellowship in relationships where we are not united. The God who brings his people into saving union with himself in Jesus Christ is the same God who divides families for the truth’s sake. Christ said of himself, “Think not that I am come to send peace on earth: I came not to send peace, but a sword” (Matt. 10:34). Christ did not come to bring peace on the earth, but a sword. That is, Christ did not come to bring earthly peace. Christ did not come to this earth to bring peace according to how man evaluates peace. Rather, Christ came to bring a sword. And what does Christ do with that sword?

35. I am come to set a man at variance against his father, and the daughter against her mother, and the daughter in law against her mother in law.
36. And a man’s foes shall be they of his own household. 
37. He that loveth father or mother more than me is not worthy of me: and he that loveth son or daughter more than me is not worthy of me. (Matt. 10:35–37)

If we esteem earthly peace with our families and friends more than we esteem the confession of Christ and his truth, then we are not worthy of Christ. Even worse, we deny Christ. And whoever denies Christ before men, him will Christ deny before the face of his Father (v. 33).

Unity is one of the greatest gifts that God gives to his church in the world. Unity in the truth of God’s word and in the confession of Jesus Christ forms the foundation of all true fellowship in all our relationships, whether that be the relationship of husbands and wives, parents and children, grandparents and grandchildren, or friends with friends. “Can two walk together, except they be agreed?” (Amos 3:3). Unity with those who are of a same mind and heart as himself is of great importance to the believer. He strives after it. He pursues it. He endeavors to keep it. Even now, Christ is busy at work gathering all his people by his word and Spirit and will be until he returns. The unity of the people of God into one in Jesus Christ is the very purpose for which God preserves this present world. Whenever all of God’s people are gathered, then will Christ come gloriously to gather all his chosen ones to himself to dwell with him in heaven, where there is perfect peace.