The following blog post was originally published on February 25, 2015. —ed.
Exactly two years ago, as the Roman Catholic Church was preparing to elect its current pope, the GTY blog published several articles from John MacArthur exposing the heresies of the Catholic Church. With the papal election dominating the news cycle and public conversation, we wanted to help our readers understand the true nature of the Catholic Church and its doctrinal distinctives.
As you might suspect, that series was met with plenty of resistance. Surprisingly, though, the majority of the criticism did not come from Catholic apologists, but from evangelicals. Many men and women who were sympathetic to the Catholic Church—including some with significant influence in evangelical circles—were critical of the firm biblical stance we took, wishing that we were more accommodating and conciliatory.
Of course, ecumenism is nothing new. Satan always works to mingle the truth with error, and the evangelistic co-belligerence of evangelicals and Catholics is just one example. But for some reason, this unlikely doctrinal mashup has been growing in popularity for the past two decades.
Evangelicals and Catholics Together?
One significant flashpoint was the development of the Evangelicals and Catholics Together (ECT) document in 1994. That incongruous union was essentially an accord between Evangelicals and Catholics regarding their agreement on various social issues. But much of the twenty-five page document was more about affirming doctrinal similarities, not shared social goals.
In effect, it painted over several important doctrinal differences and blurred the distinctions of two very dissimilar views of justification—that is the doctrine of how a person is made right with God.
Perhaps worst of all, built into ECT was an agreement to halt evangelistic efforts between evangelicals and Catholics. Under the heading “We Witness Together,” it said, “In view of the large number of non-Christians in the world and the enormous challenge of our common evangelistic task, it is neither theologically legitimate nor a prudent use of resources for one Christian community to proselytize among active adherents of another Christian community.” In effect, signing ECT was agreeing to disagree on the true means of justification, but agreeing that either means was valid for salvation. What better way for Satan to cut off millions from the reach of the gospel?
In a landmark interview called “Irreconcilable Differences,” alongside Dr. R.C. Sproul and Dr. D. James Kennedy, John MacArthur explained the biblical problems with ECT this way:
To borrow the language of the apostle Paul, any attempt at self-righteousness, no matter how noble the effort, no matter how frequently the God vocabulary is used and the divine is brought into it, any attempt to self-righteousness Paul classifies as skubalon in Philippians 3. That word is about as vivid a word as he could possibly use. It can be translated rubbish, the most accurate translation is dung. . . . And what you’ve got is a whole system built on skubalon, and you can’t throw your arms around that system. You can’t embrace it and simply say, “Well, they talk about Jesus and they talk about God and they talk about faith and they talk about grace and we’ve got to embrace them. And if we don’t embrace them, we’re violating the unity of the body and we’re being ungracious to other disciples.” That is a frightening misrepresentation of the distinctiveness of justification by faith and faith alone.
When it comes to the means of justification, there is simply no way to biblically bridge the vast chasm between evangelical and Catholic teaching. In fact, from the Catholic perspective, such partnerships have damning consequences.
Nothing Has Changed Since Trent
In response to the Reformers’ relentless assault, Rome formed its own Counter-Reformation, hoping to regain the authoritative ground it had lost. One key facet of their response was the Council of Trent, convened by Pope Paul III from 1545 to 1563. Trent was an opportunity for Rome to clarify and codify its dogma, specifically regarding salvation and other doctrines that were under fire from the Reformers. In that regard, Trent stands as one of the most influential and important councils in the history of the Catholic Church.
In short, the Council of Trent pronounced damnation on every major aspect of soteriology that the Reformers taught. In particular, it denies justification by faith alone.
If any one saith, that by faith alone the impious is justified; in such wise as to mean, that nothing else is required to co-operate in order to the obtaining the grace of Justification, and that it is not in any way necessary, that he be prepared and disposed by the movement of his own will; let him be anathema. (Canon IX)
Anathema, according to Catholic theology, means the excommunication and exclusion of a sinner from the members of the faithful. Roman Catholic theology therefore pronounces a curse of excommunication and damnation on anyone who preaches or believes that you are saved by grace alone through faith alone in Jesus.
Trent was certainly not framed by postmodern philosophers. They were explicitly clear in their rejection of the gospel that born-again Christians love and cherish:
If any one saith, that the justice received is not preserved and also increased before God through good works; but that the said works are merely the fruits and signs of Justification obtained, but not a cause of the increase thereof; let him be anathema. (Canon XXIV)
Trent anathematized every core doctrine of the Reformers. And regardless of Rome’s current attempts to extend olive branches to the evangelical church, the doctrines established at Trent are still binding on all Catholics.
Setting Sanity Aside for the Sake of Unity
Roger Olson is one of many evangelical scholars who abandon reason and doctrinal lines of demarcation in support of unification between Catholics and evangelicals.
Olson’s postmodern doublespeak exposes the poor logic of his argument. On the one hand, he admits that the Council of Trent condemned the core Protestant doctrines of the Reformers as damnable heresies.  Roger E. Olson, The Story of Christian Theology: Twenty Centuries of Tradition and Reform (Downers Grove, Illinois: Intervarsity Press, 1999) 444. He also admits that the teachings of the Council of Trent are still binding on all Catholics and to reject any of them is to renounce Catholicism and apostatize from their religion.  Ibid., 445.
But in complete disregard of his own assessment, Olson contends that the boundaries between Catholicism Protestantism are becoming “more elastic and flexible.”  Ibid., 598. He looks “forward to a day when Catholics and Protestants will enjoy full communion and fellowship.”  Ibid., 599. This is clear defiance against the law of non-contradiction. If rejecting the Council of Trent is an act of renouncing one’s Catholic faith, then it is impossible for Catholics and Protestants to “enjoy full communion.” Anathematizing your guests makes for an awkward “Kumbaya” around the ecumenical campfire. The only way Catholics and Protestants can come together is if one or the other—or both—renounce their faith.
Olson’s inconsistencies are not that surprising–he has a track record of leaning liberal on key theological issues. But far more vexing is the behavior of renowned Reformed theologian J.I. Packer. Packer has written some truly great works on Christian soteriology. His book Knowing God is rightly treasured by Bible-believing Christians all over the world. Packer has a tremendous grasp of the fundamental doctrines advanced by the Reformers—salvation by grace alone, through faith alone, in Christ alone, on Scripture alone, for the glory of God alone. His shorter work, Evangelism and the Sovereignty of God, is a helpful and clear testimony that the doctrines of grace no way mitigate fervent evangelism.
In light of Packer’s sound and robustly Reformed theology, his signature on the ECT document is troublesome. The thought of him setting aside such precious and glorious biblical truths for the sake of a unity that undermines those very truths is scarcely believable.
Roger Olson and J.I. Packer are just two examples of influential theologians who should know better than anyone that, given Roman Catholic dogma, there is no way to reconcile Catholicism and Protestantism. And yet they join many others in an endeavor that undercuts the very saving gospel they proclaim.
Missing the Mission Field
We live in a time of enormous compromise, driven by the postmodern version of tolerance. Wavering on the fundamental soteriological differences between Catholicism and evangelicalism for the sake of superficial unity is foolishness.
Twenty years ago, John Macarthur warned the church about prizing ecumenical unity over doctrinal integrity. His words are just as poignant today:
In a time like this of tolerance, false teaching will always cry intolerance; it will always say you’re being divisive, you’re being unloving, you’re being ungracious because it can only survive when it doesn’t get scrutinized. And so it cries against any intolerance. It cries against any examination, any scrutiny, just “let’s embrace each other, let’s love each other, let’s put all that behind us.” False doctrine cries the loudest about unity. And listen carefully when you hear the cry for unity because it may be the cover of false doctrine encroaching. And if ever we should follow 1 Thessalonians 5 and examine everything carefully, it’s when somebody is crying “unity, love, and acceptance.”  Irreconcilable Differences: Catholics, Evangelicals, and the New Quest for Unity, Parts 1-3
The church must be bold and clear about exposing the heresies of the Catholic Church. We must protect the flock from the ecumenical overtures of Catholics who want to suggest that we all play for the same team.
Furthermore, it must be done out of a desire to reach the vast mission field being overlooked right on our doorstep. In fact, there is perhaps no mission field riper for spiritual harvest than the Catholic Church.
One cannot help but wonder how much confusion has been spread through the evangelical church by its leaders’ ecumenical capitulation. How many people who look up to J.I. Packer and others like him have aborted the thought of witnessing to Catholics because their theological mentors were willing to link arms with Rome as colaborers in the Great Commission? Woe unto us if we allow that to pour water on our zeal to win Catholics to Christ.