Those who are really serious about unity are not serious about unity. Today we are exhorted on every side by appeals for more “unity within fundamentalism” and even more “unity between fundamentalists and conservative evangelicals.” And there are all sorts of ways proposed to get unity: prayer meetings, conferences, and public relations committees. “We must have unity,” we are told. “We must avoid the dangers to unity,” we are told. We find these sorts of appeals somewhat dubious.
Before we can moralize on the value of unity, we must realize what unity is and how it is obtained. These questions are closely related. Christian unity is spiritual “one-ness” over the Christian gospel. You cannot have Christian unity in any sense with an unbeliever, for he is not a Christian. Because Christian unity is spiritual, it is by necessity invisible. It cannot be seen. John 17:20-26 underscores this. We are united with Christ, who is united to the Father. Please note: Jesus’ unity with the Father is spiritual. It is invisible. You cannot point to their unity, and say, “Ah there it is!” Their union exists because they are God the Father and God the Son; they are one in nature. They are not united for the sake of being together. Unity is the necessary consequence of monotheism. Yea, an unavoidable consequence. Moreover, God has given to the Son glory, which glory he displayed to us in his crucifixion, resurrection, and ascension, yet actually originates before the Son became incarnate and before he was sent–a glory with no beginning. This is the glory of the divine nature, stemming from his being very God, the eternally begotten Son of God–the very glory he veiled in taking on the form of a servant. The glory arises from Christ’s divine nature. Christ, in turn, mysteriously allows us who believe in him to share in this Divine glory by giving the glory to us. That is, he allows us to share in the divine nature. It is here that we hold our hands over our mouths and acknowledge great mystery. And as we are made partakers of his glory through participation in the divine nature, we are one–one with him, one with Them, one with others who are thus united. Notice here that our unity together with other believers is based on our union with Christ. And this is not your ordinary union. As we are in him, Jesus gives or imparts to us the glory that God manifested in him from eternity past–the glory of the only begotten Son of God. And by sharing in this glory we are united to the Triune God. We are thus united with all other believers, both dead and living, who likewise share this divine nature with us. We are all one, sharing in the glory of the divine nature. Our unity with other believers, just as our unity with the Triune God, is based on our union with Jesus Christ. We have him in common.
Moreover, our spiritual unity with other believers is more or less depending upon the faith and knowledge of the Son of God. This is taught in Eph 4. We have more unity with those who cherish the gospel more. Faith brings unity. The knowledge of the Son of God brings unity. God gave the church her leaders so that the church may be more unified in the faith and knowledge of the Son of God. You cannot tell a church to be more unified. You can proclaim Christ, and, as the church grows in her faith in and knowledge of him, she will grow in her unity. The more "knowledge" (i.e., doctrine) of the Son of God is held in common, the more unity. Less common knowledge, less unity.
Particularly important here is the fact that the knowledge is the "knowledge of the Son of God." That is, as the doctrine more closely relates to Jesus Christ and the gospel concerning him, the more crucial that knowledge is for the end of unity. A debate over the mode of baptism, though important, is still less important than a debate on the hypostatic union or divinity of Christ. My disagreement with another over the interpretation of 1 Timothy 2:15's "woman shall be saved through bearing children" (depending on the nature of the disagreement), though important, is still less important than my disagreement with one who denies the substitutionary atonement or inerrancy. The latter are more directly tied to the core of the gospel message and the knowledge of Jesus Christ than the former.
All this is somewhat akin to how C. S. Lewis describes friendship in The Four Loves: “Friendship must be about something, even if it were only an enthusiasm for dominoes or white mice. Those who have nothing can share nothing; those who are going nowhere can have no fellow-travellers.” Consider another observation from the same book: “We picture lovers face to face but Friends side by side; their eyes look ahead.”
And, by the way, this is why pretensions of unity are so vulgar. They who advocate the pretensions of unity misunderstand how unity happens and what it is. We could never act like we share Christian unity with a liberal apostate, or with someone who denies the Trinity. He denies the very thing we could ever be unified over. Yea, he despises the thing we cherish most dearly. And this is also why we search in vain to find great unity with what Machen called the “indifferentists.” They have betrayed the gospel by calling the wolves sheep. They have attempted to convince us that our enemies are fighting on our side. They are traitors.
The next time someone tries to tell you that you can get more unified with some gimmick or by reducing your understanding of "separation," remember that Christian unity, at least, is not quite so easy, and cannot be contrived. Those who are serious about unity are serious are not serious about unity at all–but about the faith and knowledge of Jesus Christ.
*This revised article of mine originally appeared July 7, 2005 in the now defunct yet legendary blog administered by the good master Joel Zartman, http://www.unknowing.typepad.com.