In my last article, we went over why atheism as a position ultimately fails, and how the Three M’s (Morality, Motion and Maths) all point towards the Christian God. Not a vague cosmic force: a moral lawgiver, a sustainer, an eternal mind. A personal God, who has acted in history.
Naturally, the next question: whose church? In most of the English-speaking world, Christianity has meant Protestantism for five hundred years. But familiarity is not truth, so here are my top seven reasons why I am not a Protestant, which is to say, why I am Catholic.
As before, these are in no specific order, and no single one is meant to be the clincher. They go together, and they are far from the only ones.
1. Sola Scriptura
Sola scriptura (Scripture alone), is the principle the Reformation was built on. But the early Church had no New Testament canon at all. For three centuries she preached, baptised and went to the lions without one. The first canon of exactly the twenty-seven New Testament books we use today appears in a letter of St Athanasius in 367, and the councils that confirmed it also confirmed the seven Old Testament books the Reformers would later throw out.
What held the Church together in the meantime was the tradition St Paul commands his readers to keep, “either by our spoken word or by our letter” (2 Thessalonians 2:15). Even the usual proof text, that Scripture equips the man of God “for every good work” (2 Timothy 3:17), was written about the Old Testament; the New was not finished yet.
Ask many Christians in evangelical traditions what the pillar and foundation of the truth is, and they will say Scripture. Paul says otherwise: the “pillar and bulwark of the truth” is “the church of the living God” (1 Timothy 3:15). As St Augustine, the Reformers’ favourite Father, put it: “I would not believe the Gospel unless the authority of the Catholic Church moved me to do so.” You cannot have the Bible without the Church that put it together. For those who rely on Scripture alone, it remains an important question how a fallible historical process could yield an infallible collection of books.
2. No Rule of Faith
Words need interpreters. Twelve years after the ninety-five theses, Luther and Zwingli sat at Marburg and could not agree on what “This is my body” meant, with no one above them to settle it.
That is the structure of the whole thing: every man interprets the Scriptures for himself, and every confession binds only as far as the private judgement that adopted it. Take the Creed’s line “He descended into hell”. For the church Fathers, that is Christ’s soul descending to the realm of the dead. For Calvin, it was Christ suffering the pains of the damned. Same four words, two different meanings. The Catholic Church still has what the early Church had: a rule of faith, a living authority that can tell you what the words mean.
Catholics recite the Nicene Creed every Sunday as a rule and guide, and behind the Creed stands the same teaching office that wrote it. A shared rule of faith is not a restriction, but a grace that safeguards who Jesus is across generations.
3. Rehashing Old Heresies
The great councils did not invent doctrines; they ruled errors out, and the Church keeps their rulings the way a family keeps its memories. Whether Mary may be called the Mother of God was settled at Ephesus in 431, because her Son is one person, not two. Whether Christians may make and honour sacred images was settled at the Second Council of Nicaea in 787. Whether the Old Testament may be set aside was settled against Marcion in the second century. Every one of those questions is being asked again somewhere today.
When Christian communities move away from the early ecumenical councils, they risk reopening debates that the early Church had already resolved. There is no Christianity without historic dogma, and no dogma without the authority to define it. The Church, as Chesterton put it, is the only thing that saves a man from the degrading slavery of being a child of his age.
4. Apostolic Succession
Since Christianity is true, it makes sense to look at its founding, and at what the faith looked like in its original form. Christ did not leave behind a book; He left behind a Church. He taught and ordained the apostles, gave them the power to bind and loose (Matthew 16 and 18) and to forgive and retain sins (John 20), and at Pentecost that small apostolic body received the Spirit and went out into the world as the Church. So who did the apostles teach and ordain? And who did those men ordain in turn?
The New Testament itself starts the chain. In the first chapter of Acts, the apostles replace Judas, quoting the psalm: “his office let another take.” The Greek word for that office is episkopē: the office of a bishop.
From the very first chapter of the Church’s story, authority is something handed on, not something claimed. Around the year 96, Clement of Rome writes to settle a dispute in faraway Corinth, likely while the apostle John still lived, and records that the apostles appointed successors and ordered the line to continue. A key mark of apostolic continuity is: does the line of ordination run unbroken back to the apostles? The Catholic Church’s does.
And one apostle held more than the others. To Peter alone Christ gave the keys of the kingdom, and the keys are an office: in Israel’s royal court they belonged to the steward, who governed the house in the king’s name and passed the office on as long as the kingdom stood (Isaiah 22).
You do not give a man the keys of an office meant to die with him. That is the claim of the papacy, and it is why Rome settling Corinth’s affairs in the year 96 matters: the steward was already doing his job. The stakes are exactly as high as they sound.
As the Catholic apologist Joe Heschmeyer puts it in his book ‘Pope Peter’: “If the doctrine of the papacy is true, everyone should be Catholic. If the doctrine of the papacy is false, no one should be Catholic.” This is what moved St John Henry Newman: “To be deep in history is to cease to be a Protestant.” None of this is said against anyone’s sincerity; the Church calls other Christians separated brethren, and means both words.
5. The Four Marks
Another way to find the true Church is to run the test St Paul left us, the four marks the Creed gathers up and Christians of nearly every kind still profess every Sunday (Ephesians 2, 4 and 5). One. Holy. Catholic. Apostolic.
One: there are today thousands of Christian denominations teaching different, often contradictory things, on baptism, on the Supper, on how a man is saved. Truth does not contradict itself; if one body says the Supper is a symbol and the next says it is the Body of Christ, somebody is wrong. “Is Christ divided?” Paul asked (1 Corinthians 1:13). The usual answer is that the true Church is invisible, spiritually one across the denominations. But the Church is Christ’s Body, and His Body was not a ghost; there are not multiple Bodies of Christ.
Catholic: the word means universal. Ignatius of Antioch, on his way to martyrdom around the year 107, gave us its first recorded use, “Wherever Jesus Christ is, there is the Catholic Church”, and he meant a bishop, an altar and a people, not an idea. A church of one nation, one language or one century does not qualify. Neither does one founded in 1517. As for apostolic, that was the previous reason. And holy is where this list ends.
6. The Loss of Sacramental Liturgy
What did that original Church’s worship look like? We know, because St Justin Martyr wrote it down for the emperor around 155: the memoirs of the apostles read aloud, a homily, prayers, bread and wine brought forward, thanks given, and “the food we call Eucharist” received only by the baptised. Read that in any Catholic parish today and you will recognise it line by line. It is the Mass. And a Mass is not merely a service: a service is something you attend, a sacrifice is something offered. The Didache, before the first century was out, already applies Malachi’s prophecy of a “pure offering” among the nations to the Eucharist.
The Bible itself is a liturgical book, written to be read aloud in ordered worship; for most of Christian history, that is the only way most Christians ever met it. Christian worship was ordered from the beginning, heir to the synagogue and the Temple, and at its centre stood an altar, not a pulpit or presentation platform.
God has never treated worship as a matter of taste; read Leviticus and see how much He prescribes. The first Reformers understood this too: Luther kept most of the shape of the Mass, and the old Anglican prayer book still reads like a translation of it. A Catholic at Mass today is doing what Justin’s congregation did almost nineteen centuries ago, line by line.
7. Lack of Spiritual Works
The last reason is about what a faith produces; by their fruits you will know them. In the Catholic Church, fasting and almsgiving, the works of mercy, are central and constantly urged: the liturgical calendar itself gives the orders. The same Church produced the desert monks, the Rule of St Benedict, the vows of poverty, chastity and obedience that the Reformation abandoned, and the orders that built the hospitals, schools and universities of the West.
This is not to imply individual Christians are not kind or generous; many are. It is a point about structure. A theology that risks decoupling works from salvation will, over time, stop asking for them. A Church with the authority to command a fast and receive a vow keeps asking. The Church that teaches “faith without works is dead” has been building for two thousand years.
What the seven add up to
Taken together, the seven describe one thing: a Church that existed before its Bible, chose its Bible, wrote its Creed, ordered its worship, guarded its doctrine and produced its saints, continuously, from a room in Jerusalem to a parish down your road. Christ made one promise about that Church: that the gates of hell would not prevail against it (Matthew 16:18). I went looking for the Church that promise describes. I found her.
- Why I Chose Catholicism: 7 Reasons - October 7, 2026
- Why I Am Not an Atheist: The Three M’s - September 28, 2026
- “Help, the Pope said something I disagree with” - July 20, 2026
