“That they may all be one; even as Thou, Father, art in Me, and I in Thee, that they also may be in Us; that the world may believe that Thou didst send Me.” (John 17:21).

In a videotape titled “The Pope: The Holy Father,” Catholic apologist Scott Hahn claims the proliferation of Protestant denominations proves the Reformers’ principle of sola Scriptura is a huge mistake:

Do you suppose that Jesus would say, “Well, once I give the Church this infallible Scripture, there really is no need anymore for infallible interpretations of Scripture. The Church can hold together just with the infallible Bible.”

Oh, really? In just 500 years, there are literally thousands and thousands of denominations that are becoming ever more numerous continuously because they only go with the Bible. It points to the fact that we need an infallible interpretation of this infallible book, don’t we[?] ( Here’s a link to a full transcript of the videotape .)

A tract titled “ Pillar of Fire, Pillar of Truth ” (published by Catholic Answers) makes a similar charge:

The “Bible alone” theory simply does not work in practice. Historical experience disproves it. Each year we see additional splintering among “Bible-believing” religions. Today there are tens of thousands of competing denominations, each insisting its interpretation of the Bible is the correct one. The resulting divisions have caused untold confusion among millions of sincere but misled Christians. Just open up the Yellow Pages of your telephone book and see how many different denominations are listed, each claiming to go by the “Bible alone,” but no two of them agreeing on exactly what the Bible means.

That is a favorite argument of Catholic apologists. They are convinced that the unity Christ prayed for in John 17:21 is an organizational solidarity that is incompatible with both denominationalism and independency. As far as the Roman Catholic Church is concerned, the only way true Christian unity will be fully and finally achieved is when “separated brethren”—non-Catholic Christians—reunite with Rome under the authority of the Pope.

Keith Fournier, Catholic author and Executive Director of the American Center for Law and Justice, sums up the typical Roman Catholic perspective:

Throughout Christian history, what was once intended to be an all-inclusive (catholic) body of disciples of the Lord Jesus Christ has been fractured over and over. These fractures threaten to sever us from our common historical and doctrinal roots. I do not believe that such divisions were ever part of the Lord’s intention, no matter how sincere or important the issues that undergirded the breaking of unity. [Keith A. Fournier, A House United? (Colorado Springs: NavPress, 1994), 37.]

Fournier says he is “not advocating a false non-denominationalism or superficial irenicism that denies distinctives of doctrine or practice.” [Ibid.] But note that he is suggesting that doctrinal differences, “no matter how . . . important,” should not cause organizational divisions. Moreover, fewer than five pages earlier, he had berated those who “fight over theology.” [Ibid., 25.] And (ironically) just a few pages before that, he had expressed outrage at John MacArthur, R.C. Sproul, and Jim McCarthy for saying they believe Roman Catholicism’s rejection of justification by faith alone is “doctrinal error” [Ibid., 21-22.]

Notice carefully, then, what Fournier is saying: He claims he wants unity without “superficial irenicism,” and yet he objects when anyone contends for sound doctrine or (worse still) labels Roman Catholic doctrine “error.” It seems the “unity” Fournier envisions is merely the same kind of unity the Roman Catholic Church has sought for hundreds of years: a unity where all who profess to be Christians yield implicit obedience to Papal authority, and where even individual conscience is ultimately subject to the Roman Catholic Church.

Although Fournier politely declines to state who he believes is to blame for fracturing the organizational unity of Christianity, [Ibid., 29.] it is quite clear he would not be predisposed to blame a Church whose spiritual authority he regards as infallible. And since the Catholic Church herself officially regards Protestantism as ipso facto schismatic, Fournier’s own position is not difficult to deduce. Although Fournier manages to sound sympathetic and amiable toward evangelicals, it is clear he believes that as long as they remain outside the Church of Rome, they are guilty of sins that thwart the unity Christ prayed for.

Of course, every cult and every denomination that claims to be the One True Church ultimately takes a similar approach to “unity.” Jehovah’s Witnesses believe they represent the only legitimate church and that all others who claim to be Christians are schismatics. They believe the unity of the visible church was shattered by the Nicene Council.

Meanwhile, the Eastern Orthodox Church claims the Church of Rome was being schismatic when Rome asserted papal supremacy. To this day, Orthodox Christians insist that Eastern Orthodoxy, not Roman Catholicism, is the Church Christ founded—and that would make Roman Catholicism schismatic in the same sense Rome accuses Protestants of being schismatic. One typical Orthodox Web site says , “The Orthodox Church is the Christian Church. The Orthodox Church is not a sect or a denomination . We are the family of Christian communities established by the Apostles and disciples Jesus sent out to proclaim the Good News to the world, and by their successors through the ages.”

All these groups regard the church primarily as a visible, earthly organization. Therefore they cannot conceive of a true spiritual unity that might exist across denominational lines. They regard all other denominations as schismatic rifts in the church’s organizational unity. And if organizational unity were what Christ was praying for, then the very existence of denominations would indeed be a sin and a shame. That’s why the Orthodox Web site insists, “The Orthodox Church is not a sect or a denomination.”

Furthermore, if their understanding of the principle of unity is correct, then whichever organization can legitimately claim to be the church founded by Christ and the apostles is the One True Church, and all others are guilty of schism—regardless of any other doctrinal or biblical considerations.

That is precisely why many Catholics and Eastern Orthodox have focused their rhetoric on “unity.” Both sincerely believe if they can establish the claim that they, and no one else, are the One True Church instituted by Christ, then all other Protestant complaints about doctrine, church polity, and ecclesiastical abuses become moot. If they can successfully sell their notion that the “unity” of John 17:21 is primarily an organizational unity, they should in effect be able to convince members of denominational and independent churches to reunite with the Mother Church regardless of whether she is right or wrong on other matters.

The plea for unity may at first may sound magnanimous and charitable to Protestant ears (especially coming from a Church with a long history of enforcing her will by Inquisition). But when the overture is being made by someone who claims to represent the One True Church, the call for “unity” turns out to be nothing but a kinder, gentler way of demanding submission to the Mother Church’s doctrine and ecclesiastical authority.

Nonetheless, in recent years many gullible Protestants have been drawn into either Catholicism or Eastern Orthodoxy by the claim that one or the other represents the only church Christ founded. Having bought the notion that the unity Christ prayed for starts with organizational unity, these unsuspecting proselytes naturally conclude that whichever church has the most convincing pedigree must be the only church capable of achieving the unity Christ sought, and so they join up. Many recent converts from evangelicalism will testify that the proliferation and fragmentation of so many Protestant denominations is what first convinced them that Protestant principles must be wrong.