If our ecumenical endeavors do not seek total unity in the truth — that is, in dogma, morals, government and worship — all we will be doing is simply being polite, comparing notes and opinions, making comments on our own beliefs and ending up saying, "Well, that's what we believe and, in the end, surely we worship the same God, and what really matters is what you have in your heart. So we just agree to disagree."
Is that really the fulfillment of Jesus' prayer for us to "be one as He and Father are one"? Does that mean we are intimately united among ourselves as the Persons of the Trinity are in their one nature?
God is absolute truth. If we ignore this reality, we do so at our own peril. Unity must exist in everything fundamentally Catholic: The Trinity, Christ's divinity, the necessity of baptism, the reality of the Real Presence of Jesus in the Eucharist, the role of Peter, the seven sacraments, the authority of Church to interpret Scripture, power to forgive sins and so on.
But when you find so many discrepancies and contradictions among Christian denominations, a hodgepodge of creeds and schisms, then you know that Christ is demonstrably not in that cacophony. They cannot all be true. Cacophony is not a mark of consistency; truth cannot contradict itself.
Today many "ecumenical" folks in the Church, even in the Vatican, search for the lowest common denominator and end up in an agreement on less important things and a compromising silence on the most important ones of the Faith. But as Pope St. John Paul II noted in his 1995 encyclical Ut Unum Sint, "In matters of faith, compromise is in contradiction with God, who is Truth."
The pope couldn't be more explicit about false ecumenism. The ecumenical movement must be precisely an effort that moves towards a specific goal, that of full unity, towards God's truth, away from error, not just sitting and smiling at each other and hugging one another and exchanging pleasant comments.
As Pope St. John Paul II noted in section 36 of Ut Unum Sint:
Full communion, of course, will have to come about through the acceptance of the whole truth into which the Holy Spirit guides Christ's disciples. Hence all forms of reductionism or facile "agreement" must be absolutely avoided. Serious questions must be resolved, for if not, they will reappear at another time, either in the same terms or in a different guise.
We must move towards the New Jerusalem, the heavenly city, the Bride of Christ, the house of God, which was not built upon the moving sands of individual opinions, but upon a rock — as in the parable — a rock, Peter.
Jesus founded a Church in which the Apostles were the first bishops, and He chose one of them to be the head. The rest is history.
Yes, many churches (from the "reformation" of Christianity, or rather, the deformation of Christianity) have elements of truth — some more, some less. But we are not and cannot be satisfied with the partial truth mixed up with error. We can only be satisfied with the fullness of the truth, which is found only in the Catholic Church, as John XXIII taught in his 1961 Mater et Magistra: "Mother and Teacher of all nations — such is the Catholic Church in the mind of Her Founder, Jesus Christ. ... She is 'the pillar and foundation of the truth' (1 Timothy 3:15)."
Let us remember the basic difference between true and false ecumenism: True ecumenism is to bring all peoples into one single Church; false ecumenism is to bring all churches into one single people.
Regarding those who think otherwise, especially in the Hierarchy, Jesus warns us, saying: "Beware of false prophets, who come to you in sheep's clothing, but inwardly they are ravenous wolves" (Matthew 7:15); and "Not everyone that says to me, 'Lord, Lord' shall enter into the kingdom of Heaven. But he that does the will of my Father who is in Heaven, he shall enter into the kingdom of Heaven" (Matthew 7:21).
An enlightening example happened when Japanese bishops went to Rome in their ad limina visit and spoke with the pope. Bishop Toshio Oshikawa told Vatican Radio that there are only 447,000 Catholics in Japan's population of 130 million because it is regarded by many as a "Western product." Because of this, the bishops are promoting the inculturation of the Christian faith.
Those bishops have not studied the encyclical Evangelii Nuntiandi of Paul VI, where he teaches that "pre-Christian religions must be purged by the gospel." That is, those elements incompatible with the gospel must be purged. Much discernment is necessary.
John Paul started by reminding them of the highly successful apostolate of St. Francis Xavier, a Western missionary who converted thousands of Japanese to the true Faith. The converts had great faith and are the model for today and the future.
"Inculturation," the pontiff said, must not be the product of a committee. According to John Paul II, it must consist of "translat[ing] the truths of the Faith into categories more readily accessible to Asian sensibilities and the mentality of your people. The challenge is to present the 'Asian face of Jesus' in a way that is in perfect harmony with the Church's whole mystical, philosophical and theological tradition."
John Paul II emphasized that the clergy must set the example, as "the work of St. Francis Xavier and the first missionaries, which has borne such fruit in the past, will continue to bear abundant fruit as long as their memory is cherished and venerated."
The message could not be clearer: A return to the preaching and the prayer life of the original missionaries — like St. Francis Xavier — will produce the call to holiness that the Church needs, not only in Japan, but all over the world. And the promotion of authentic ecumenism, ecumenism aimed at bringing everyone to the fold of Christ, must be the goal and purpose of evangelization.
No mixture of Christianity with heresy (as in the case of the many denominations of Protestantism) or with paganism (as in the case of the Pachamama or Islam) will ever be the mark of authentic Christian mission.
These final quotes from Pope John Paul II are well worth remembering: