Catholics and Their Interaction with Other Religions in Contemporary Society


Contemporary Western society’s preponderant secular relativistic thought tendencies contend that all beliefs are to be deemed worthy of being considered as equally true. The philosophical concomitant outgrowths of this thought place spotlight on, among others, four fashionable terms: “inclusivity,” “accommodation,” “toleration,” and “diversity,” all understood wrongly, and all of which have increasingly been adopted by some Catholic institutions, especially a number of Catholic colleges and universities (rather to be considered, rightfully and in actuality, marginally Catholic or not nearly Catholic at all). Unfortunately, these institutions are ignorant of the logical implications of these secular philosophical ideals, of their philosophical origins, and of their philosophical incongruity with Catholic teaching, understood rightly.

In the midst of the infatuations with these ephemeral philosophical ideas amongst the many of society, it is of great importance for Catholics to consider the following question: What does the Catholic Church teach about how Christians must interact with other religious faiths, beliefs, ideals, and traditions? By exploring Catholic philosophical thought, Church teaching, and Catholic exegesis, all understood rightly, one can endeavor to find guidance on the above question.

It would be the case that those of the Church who attempt to apply the contemporary societal relativistic philosophical ideal that all beliefs are equal in their stations, as well as the ideal’s outgrowths and implications, interiorly to Church thought are rejecting, to use guidance from Church theology, that the Father sent his only begotten Son who took on human flesh and was crucified in order to testify to the truth. If all religious beliefs are to be deemed equally true, then the necessary implication of this assertion is that the birth, ministry, Passion, death, and Resurrection of Jesus Christ were of no particular significance. Thus the Christian man who argues that all religious beliefs are equal — which the Congregation For the Doctrine of Faith under Pope Benedict XVI termed “religious relativism”1 — is not truly inclusive in nature, but this man is actually exclusive of Jesus Christ. In short, the man in this case is attempting to be “inclusive,” as society sees it, but in all actuality the man is excluding the primacy of Jesus Christ and the teachings of His Church.

One must recall that the Catholic Church views itself as a timeless institution. The Church considers itself to be a body — one comprised of finite and fallible human beings — that through the centuries seeks understanding of truth, insofar as man can comprehend it, find it, and understand it.

As preeminent Church philosopher Saint Thomas Aquinas argues, understanding of truth — that is, understanding of reality — requires the rational part of the soul, for: “The notion of the true consists in the adequation of thing and intellect.”2 Man searches for truth, the discoverable kind, by utilizing the rational part of the soul. Man tries to understand as best as he possibly can, however inadequate are his abilities, for as Paul acclaimed: “Oh, the depth of the riches and wisdom and knowledge of God! How inscrutable are his judgements and how unsearchable his ways!”3

As a body, then, that seeks to understand truth, the Church does not attempt to create first principles. As another eminent philosopher of Church history, Saint John Paul II, declares: “Sure of her competence as the bearer of the revelation of Jesus Christ, the Church reaffirms the need to reflect upon truth.”4

If the Catholic Church considers itself to be the “bearer of the revelation of Jesus Christ”5 and it requires itself to “reflect upon truth,” then both reason and faith, as Thomas Aquinas would argue, is requisite.

Further, as a timeless institution searching for the truth — which always was, is, and forever shall be, and which subsists independently of society’s whims and bows subservient never to its fads and fashions — the Church must be impenetrable to the interference of outside ideologies and thought, if rather than helping it understand truth, they influence Church philosophical thought processes and require or encourage the re-definition of first principles interiorly. From its beginning, the Church has struggled to resist outside societal influences. Even though the latest ideals fancied by the many, and whoever are and whatever are their leaders and influences at any given time, will wither, they nonetheless cause destruction while alive and continue to do so even after the diminishment of their influences and their expirations or death.


Church teaching instructs believers that it is their absolute duty to love all people and that they must recognize always the inherent dignity of each and every person. That instruction does not mean, however, that others’ religious beliefs must be accepted as equal to those held by trinitarian Christians. Jesus said that “The Father and I are one.”6 To the Apostle Thomas, Jesus declared that “no one comes to the Father except through me.”7

It was God’s plan to save man through His Son, who Himself said: “Whoever does not honor the Son does not honor the Father who sent him.”8 It was the will of the Father to send his only begotten son in order to show man more fully the way to the truth.9 As the Lord himself said: “Whoever loves me will keep my word, and my Father will love him, and we will come to him and make our dwelling with him.”10 Man, through the Church, may take hundreds or thousands of years to understand every intracity of the faith, but the most important of truths have been given in simple words: that all most love Jesus and follow His commands.

Other religions do not believe in the divinity of Jesus and the Holy Spirit (and alongside nontrinitarian Christians, reject the essence of God as being of three persons). For the Church, the Trinity represents the complete essence of God. To know God, one must recognize and worship all three persons of the one Godhead

Some in the contemporary Catholic Church, even as Christian martyrdom, suffering, and sacrifice continue daily around the world, are reticent in speaking the truth, having been influenced by the secular culture and its pressures to conform to their totalitarian dictates. The real greatest act of love, however, would be to bring others to the truth of Christianity, understood rightly.

The Church’s bishops, priests, and consecrated must resist, as difficult as it may be at times, to speak and to write in politically-correct platitudes so as not offend or upset. Judging is only left to God, for Jesus said: “For as you judge, so will you be judged, and the measure with which you measure will be measured out to you.”11 Saving souls, the primal duty of the bishop and priest, however, requires teaching, which is of another genus than is judgement. The Church sees Catholic teaching not to entail judging, but rather to be instruction on what actions one must take in order to be saved. God judges, but Catholic teaching provides the instructions — insofar as man can know — on how one must act in order to be judged favorably by God. Church Canon Law declares that “the salvation of souls . . . must always be the supreme law in the Church.”12 This principle of salus animarum suprema lex13 requires that men are taught properly how to save their souls.

Those charged with the power to teach in the Church must speak the very words they themselves proclaimed in Vatican II’s Lumen Gentium:

the Church, now sojourning on earth as an exile, is necessary for salvation. Christ, present to us in His Body, which is the Church, is the one Mediator and the unique way of salvation. In explicit terms He Himself affirmed the necessity of faith and baptism and thereby affirmed also the necessity of the Church, for through baptism as through a door men enter the Church. Whosoever, therefore, knowing that the Catholic Church was made necessary by Christ, would refuse to enter or to remain in it, could not be saved.14

The Church teaches that salvation comes through Jesus. If one remains steadfast to the principle of salus animarum suprema lex, then one must teach properly so that men may have a fair chance at obtaining salvation. False teaching, or not teaching, then, would mean that one is not bringing the other to salvation, which is the primary duty of the episcopal and priestly classes.


The Church teaches that the Old Testament writers prophesied the Coming of Jesus Christ — that He was the One for whom the people of Israel were waiting. Jesus, who “without losing his divine nature . . . assumed human nature”15 “is the one and only mediator between God and men.”16

When Jesus appeared to the disciples in Jerusalem, He told them: “These are my words that I spoke to you while I was still with you, that everything written about me in the law of Moses and in the prophets and psalms must be fulfilled.”17 Then, writes Luke, Jesus “opened their minds to understand the scriptures.”18

As one sees in the Acts of the Apostles, the early Christians still considered themselves to be Jews, with debates among them centering on whether Gentiles could even be saved. Indeed, Acts tells the story a fledgling Church that sees itself as the rightful and proper continuation of the Judaism of the Son of Man — who as a man was conceived as a Jew, lived as a Jew, and died as a Jew. Further, in Romans 9, Saint Paul, who elsewhere calls himself “the apostle to the Gentiles” laments the Jews who have rejected Jesus as God and writes that salvation will come only with belief in Jesus.19 In Jesus, “God has visited his people. He has fulfilled the promise he made to Abraham and his descendants.”20 In a synagogue address, Saint Paul stated unequivocally that Jesus is the Jewish Messiah: “God, according to his promise, has brought to Israel a savior, Jesus.”21

Christians, then, are the heirs of the Jewish faith of the Old Testament, which consists of God’s revelation preceding Jesus’s coming. Christians today are not awaiting the Messiah’s first coming, for He has already come, but rather they stand in waiting for His second earthly sojourn when, as the Nicene-Constantinopolitan Creed declares, “He will come again in glory to judge the living and the dead.”

Since Jesus declared His New Covenant, one cannot enjoy the fruits of the Father without directing his love to the Son. For as Jesus said:

If any one comes to me without hating his father and mother, wife and children, brothers and sisters, and even his own life, he cannot be my disciple. Whoever does not carry his own cross and come after me cannot be my disciple.22

It is this teaching, that He is to be loved wholly and above all other things, that has been, is, and always will be man’s most difficult to follow.


When headed by Joseph Cardinal Ratzinger, later to become Pope Benedict XVI, the Congregation for the Doctrine of the Faith released Dominus Iesus, which affirmed that always God alone will judge who is to be saved, but which nonetheless cautioned the following:

God wills the salvation of everyone through the knowledge of the truth. Salvation is found in the truth. Those who obey the promptings of the Spirit of truth are already on the way of salvation. But the Church, to whom this truth has been entrusted, must go out to meet their desire, so as to bring them the truth.23

Dominus Iesus is a reminder that the Church is the possessor of the truth, and that she is tasked dutifully with spreading that truth.

In Acts, Peter proclaims his devotion to the name of Jesus in the face of the Jewish elite who deny Jesus’s divinity, mincing words not when he tells them: “There is no salvation through anyone else, nor is there any other name under heaven given to the human race by which we are to be saved.”24

It is of great importance to remember that the Catholic Church teaches that it has the clearest possible understanding of that which God desires, insofar as man can know and that the Holy Spirit allows man to know by His grace. It must be remembered, then, that understanding of the Holy Spirit is crucial to the understanding of God, for the Holy Spirit is One of the Three, as it was so declared at the 381 Council of Constantinople.25

The Catechism of the Catholic Church declares:

God has sent the Spirit of his Son into our hearts, crying, ‘Abba! Father!”’ This knowledge of faith is possible only in the Holy Spirit: to be in touch with Christ, we must first have been touched by the Holy Spirit. He comes to meet us and kindles faith in us. By virtue of our Baptism, the first sacrament of the faith, the Holy Spirit in the Church communicates to us, intimately and personally, the life that originates in the Father and is offered to us in the Son.26

Hence the Church teaches that in order to know the Father, one must know the Son, and to know the Son, one must know the Holy Spirit. It is the Holy Spirit who gives the gift of faith and who provides the unearned and undeserved grace that is given to man. It is the Holy Spirit who inspired directly the Old and New Testaments as well as the formation of the Canon.27 From the Paraclete man is offered the opportunity to share in His seven gifts.28 Of the Holy Spirit, Jesus said: “The Advocate, the holy Spirit that the Father will send in my name — he will teach you everything and remind you of all that [I] told you.”29

Thus Church teaching would instruct that to administer true love and care, understood rightly, for those chained in darkness with regard to the Holy Spirit and Jesus as God, would be to bring them to the light of truth. Being guided by exterior societal demands and attitudes, many blessed bishops and priests are more apt today to isolate the positive-feeling scriptures and teachings of the Church that are in accord with societal ideologies, neglecting one of the most important teachings they can impart on, and explain to, their flocks: that Jesus Himself said that there was one sin that was unforgivable: Blasphemy against the Holy Spirit. Catholic teaching, employing a great deal of insight from both Augustine and Thomas Aquinas on the topic, interprets the unforgivable sin as being one who does not accept the Holy Spirit. Saint John Paul II explains that the “unforgivable” sin is:

the refusal to accept the salvation which God offers to man through the Holy Spirit, working through the power of the Cross. If man rejects the “convincing concerning sin” which comes from the Holy Spirit and which has the power to save, he also rejects the “coming” of the Counselor — that “coming” which was accomplished in the Paschal Mystery, in union with the redemptive power of Christ’s Blood: the Blood which “purifies the conscience from dead works.”30

John Paul II further clarifies:

This means the refusal to come to the sources of Redemption, which nevertheless remain “always” open in the economy of salvation in which the mission of the Holy Spirit is accomplished.31

One cannot know the Son without be led to him by the Spirit, hence one must know the Spirit.


When Paul writes that God “who from my mother’s womb had set me apart and called me through his grace, was pleased to reveal his Son to me, so that I might proclaim him to the Gentiles,” Paul is not concerned with “inclusivity,” “toleration,” “accommodation,” and the “diversity” of other beliefs that reject Jesus Christ and the Holy Spirit.32 One must remember that respecting and loving another on principle does not correlate necessarily with having to respond in the same manner toward his beliefs. A man’s inherent dignity and the Christian duty to love one’s neighbor as a fellow child of God does not mean that one is required to love the beliefs of those who reject that Jesus and the Spirit are God.

Peter and John said to the Sanhedrin: “It is impossible for us not to speak about what we have seen and heard.”33 The representatives of the Catholic Church must speak truth, remembering that prior to the resurrection Peter denied Jesus three times, but that he was subsequently forgiven by Jesus and would ultimately die a martyr for the Lord. The Church teaches that Saint Peter died for the truth which reveals that the Trinity is God.

The Psalmist sang to God: “May the nations be glad and rejoice; for you judge the peoples with fairness.”34 Indeed, in the Catholic conception, God loves all of the children He has made and He shall judge them with equity. Jesus judged the Canaanite woman, an ostracized non-Jew, based on her faith in Him, healing her from possession by a demon because she showed great faith in Him.35 And to those who live only for earthly possessions Jesus was also not tolerant.36

For the Church, man learns of truth by way of Scripture. Thus he who desires the truth must be of the book. As explained in Dei Verbum:

For holy mother Church, relying on the belief of the Apostles, . . . holds that the books of both the Old and New Testaments in their entirety, with all their parts, are sacred and canonical because written under the inspiration of the Holy Spirit, they have God as their author and have been handed on as such to the Church herself.37

As Leo XIII explains, it is through the Scriptures that Jesus puts forth the truth:

He uses them [Holy Scriptures] at times to prove that He is sent by God, and is God Himself. From them He cites instructions for His disciples and confirmation of His doctrine. He vindicates them from the calumnies of objectors; he quotes them against Sadducees and Pharisees, and retorts from them upon Satan himself when he dares to tempt Him. At the close of His life His utterances are from Holy Scripture, and it is the Scripture that He expounds to His disciples after His resurrection, until He ascends to the glory of His Father. Faithful to His precepts, the Apostles, although He Himself granted “signs and wonders to be done by their hands” nevertheless used with the greatest effect the sacred writings, in order to persuade the nations everywhere of the wisdom of Christianity, to conquer the obstinacy of the Jews, and to suppress the outbreak of heresy.38

Scripture is a roadmap to the truth; actual “inclusivity” for the Christian requires inclusion of the New Testament as part of that guide. That guide, of course, requires faith in the trinity for those who seek union with the Father. Scripture, grace, and the workings of the Holy Spirit require a particular faith, meaning that not all beliefs are equally good and aimed properly toward the salvation of man. As John writes: “From his fullness we have all received, grace in place of grace,39 because while the law was given through Moses, grace and truth came through Jesus Christ.”40

It must be said that Jesus does not desire that any are separated from Him; rather, Christ desires that all are unified in Him. For it was Jesus Himself who prayed “for those who will believe in me through their word, so that they may all be one, as you, Father, are in me and I in you.”41 In the Catholic conception, to know the Father, the unbegotten, unprocessed, unmoved first mover, all must bring themselves to the feet of the Son, Jesus, through the grace provided by the conduit, the Holy Spirit, “Who proceeds from the Father and the Son.”42

Thus Catholic philosophical thought, Church teaching, and Catholic exegesis would instruct that Christians must love the non-believer, he of many diversities, but never his disbelief in the truth. Treating those of other religions as human beings made in the image of God and loving them as equal and as one’s neighbors, never means that the Christian must consider their beliefs to be equal in standing to his own.


This article as originally run was an earlier and incomplete draft. It has been updated (11/23/2019) to reflect the full essay.

  1. Congregation for the Doctrine of Faith, Declaration, Dominus Iesus, August 6, 2000,, no. 22.
  2. Disputed Question on Truth, Pt. I, ques. 1, art. 3, resp., in Saint Thomas Aquinas, Thomas Aquinas: Selected Writings, ed. and trans. Ralph McInerny (New York: Penguin Classics, 1998), 173.
  3. Rom 11:33, New American Bible Revised Edition.
  4. Saint John Paul II, Encyclical Letter, Fides et Ratio, reprint of Vatican translation (Boston: Pauline Books and Media), 1998, no. 6.
  5. Saint John Paul II
  6. Jn 10:30.
  7. Jn 14:6.
  8. Jn 5:23.
  9. Dogmatic Constitution on the Church, Lumen Gentium, November 21, 1964,, no. 3.
  10. Jn 14:23
  11. Mt 7:2. See also Lk 6:37, when Jesus said: “Stop judging and you will not be judged. Stop condemning and you will not be condemned. Forgive and you will be forgiven.”
  12. Code of Canon Law (Washington: Canon Law Society of America, 1983), c. 1752,
  13. James T. Bretzke, Consecrated Phrases: A Latin Theological Dictionary, 3rd ed., (Collegeville, MN: Liturgical Press, 2013), 215,
  14. Lumen Gentium, no. 14.
  15. Catechism of the Catholic Church (New York: Image, 1997), no. 479. Hereinafter, CCC.
  16. CCC 480.
  17. Lk 24:44.
  18. Lk 24:45.
  19. Rom 11:13.
  20. CCC 422.
  21. Acts 13:23.
  22. Lk 14:26–27.
  23. Dominus Iesus, no. 22.
  24. Acts 4:12.
  25. CCC 245.
  26. CCC 683.
  27. Dogmatic Constitution on Divine Revelation, Dei Verbum, November 18, 1965,, no. 11.
  28. Dei Verbum, no. 5.
  29. Original brackets. Jn 14:26.
  30. John Paul II, Encyclical Letter, On the Holy Spirit in the Life of the Church and the World: Dominum et Vivificantem, May 18, 1986,, no. 46.
  31. John Paul II, Dominum et Vivificantem, no. 46.
  32. Gal 1:15–16.
  33. Acts 4:20.
  34. Ps 67:5.
  35. Mt 15:21–28.
  36. Mk 10:17–31 and Lk 18:18–30.
  37. Dei Verbum, no. 11.
  38. Pope Leo XIII, Encyclical Letter, On the Study of Holy Scripture: Providentissimus Deus, November 18, 1893,, no. 3.
  39. As the NABRE note to the passage explains: “grace in place of grace” means the “replacement of the Old Covenant with the New”; 1184.
  40. Jn 1: 16–17.
  41. Jn 17:20-21.
  42. Nicene-Constantinopolitan Creed.
Gerard T. Mundy About Gerard T. Mundy

Gerard T. Mundy is a writer and teaches philosophy at a private college in New York City. His essays have appeared in Public Discourse, the University Bookman, Crisis, the American Conservative, and the Federalist, among others.