What do Catholics believe, and where do Reformed churches agree and differ?

Many people who visit a Reformed church for the first time come from somewhere else, and often that somewhere is the Catholic Church. If that is you, this article is meant to describe your own faith fairly, in its own words, and then to explain honestly where Reformed churches agree and where they differ. The differences are real; so is the common ground.

Catholic teaching in its own terms

The Catechism of the Catholic Church, published in 1992, is the Church’s own summary of what it believes. Its main lines are these.

The Trinity. The Catechism calls the mystery of the Most Holy Trinity “the central mystery of Christian faith and life.” God is one, in three persons: Father, Son and Holy Spirit. Jesus Christ is true God and true man, born of the Virgin Mary, crucified, risen and coming again.

Scripture and Tradition. Catholics believe God’s revelation is handed on in two ways that flow from the same source: the written Scriptures and the living Tradition of the Church, passed down from the apostles. The task of interpreting both authoritatively belongs to the Magisterium, the teaching office of the bishops in union with the pope.

Seven sacraments. Baptism, Confirmation, the Eucharist, Penance (Reconciliation), Anointing of the Sick, Holy Orders and Matrimony. Catholics believe these were instituted by Christ and that they truly give the grace they signify.

The Mass. The Eucharist is “the source and summit of the Christian life.” Catholics believe that at the consecration the bread and wine become the body and blood of Christ (transubstantiation), and that the Mass makes present the one sacrifice of Christ on the cross. Sunday Mass is an obligation, and receiving Communion is the heart of Catholic worship.

Mary and the saints. Catholics honour Mary as the Mother of God, conceived without sin (the Immaculate Conception) and taken body and soul into heaven (the Assumption). They ask Mary and the saints to pray for them, as one might ask a friend, while worship in the strict sense is given to God alone.

The papacy. The pope, as bishop of Rome and successor of St. Peter, is the visible head of the Church on earth. Under carefully defined conditions, Catholics believe his teaching on faith and morals is infallible.

Justification. Catholics believe that justification is God’s free gift, begun in baptism, by which a person is not only forgiven but inwardly renewed and made righteous. Faith, hope and love grow through the sacraments and through good works done in grace. Grace comes first; nothing a person does can earn it.

Where Reformed churches agree

Reformed Christians and Catholics confess the same Apostles’ Creed and Nicene Creed. They believe in the same triune God, the same incarnation, the same virgin birth, the same cross and empty tomb, the same return of Christ to judge the living and the dead. They read the same sixty-six books as Scripture, although Catholic Bibles also contain the deuterocanonical books. They keep the same Ten Commandments and pray the same Lord’s Prayer.

They agree that God is the author of salvation and that grace comes before anything we do. They agree that the church is one, holy, catholic and apostolic, and that a Christian life apart from the church is unthinkable. They largely agree on moral questions: the dignity of every human life from conception to natural death, the meaning of marriage, care for the poor and the stranger.

Both baptize infants. Reformed churches have long recognized a baptism performed in the Catholic Church, with water in the name of the Father, the Son and the Holy Spirit, as a true Christian baptism. A Catholic who joins a Reformed church is not baptized again.

Where they honestly differ

Authority. Reformed churches hold that Scripture alone is the final authority. Creeds, confessions and the wisdom of the church are valued, but all of them are tested by the Bible and none of them stands beside it. There is no magisterium and no pope; Christ alone is head of the church, and he governs it through his Word.

Justification. Reformed churches teach that a person is justified by faith alone: God declares the believer righteous on account of Christ’s obedience and death, credited to them, apart from anything they have done (Romans 3:28; Heidelberg Catechism, Q&A 60). Inner renewal is real and necessary, but Reformed Christians call that sanctification and keep it distinct from justification. They would say the Catholic account blends the two. Catholic and Lutheran theologians have narrowed this gap in recent decades, and both sides agree that grace is the origin; but the difference has not disappeared.

Sacraments. Reformed churches count two sacraments, baptism and the Lord’s Supper, because they find only these commanded by Christ for all his people. They do not deny that marriage, ordination and the confession of sin are good and biblical; they simply do not call them sacraments.

The Lord’s Supper. Reformed Christians believe Christ’s sacrifice was offered once for all on the cross (Hebrews 10:10–14), and that the Supper is not a sacrifice but a meal in which Christ truly gives himself to believers by his Spirit. The bread and wine remain bread and wine. This is the sharpest difference of all, and it is why Catholics and Reformed Christians do not share Communion.

Mary and the saints. Reformed Christians honour Mary as the blessed mother of the Lord (Luke 1:42–48) and thank God for the saints. But they pray only to God, through Jesus Christ, whom they believe to be the one mediator (1 Timothy 2:5), and they do not hold the Immaculate Conception or the Assumption, since they do not find them in Scripture.

Confession and purgatory. Reformed Christians confess their sins directly to God (1 John 1:9) and to one another (James 5:16); pastors and elders assure them of forgiveness from the Word. They believe that at death a believer goes immediately to be with Christ (Luke 23:43; Philippians 1:23), so they do not teach purgatory or offer prayers for the dead.

What a Catholic would notice in a Reformed service

Much would feel familiar. There is a set order of worship, printed in a bulletin. The congregation stands and sits at set points. Scripture is read, the Ten Commandments are read, the Apostles’ Creed is confessed and the Lord’s Prayer is prayed. There is a sermon, though it is longer than a homily, usually thirty to forty minutes. Bread and wine are shared at the Lord’s Supper. A blessing closes the service.

Other things would feel different. The building is plain: no altar, no crucifix, no statues, no candles, no holy water. The minister wears a suit or a plain black gown. There is no kneeling and no sign of the cross. Most of the singing is of the Psalms, often to old Genevan melodies, with organ or piano. The Lord’s Supper is celebrated only a few times a year, and only professing members and approved guests take part; visitors are not expected to. Children stay in the service from a young age rather than going out for a children’s liturgy.

A Catholic visitor would not be asked to do anything unfamiliar. You can sit, listen and follow along. If the differences described here raise questions, the minister of the local Reformed church listed on this site would be glad to talk them through with you, without any pressure to decide anything.