The non-Christian could go through all the external motions, so that the average onlooker might reasonably conclude that he received the sacrament; but in reality, nothing sacramental would take place.In other words, the sacrament would be conferred on the non-Christian invalidly.But if a Catholic marries a non-baptized person—a Muslim, let’s say—in a Catholic wedding ceremony, and if a Catholic wedding confers the sacrament of matrimony on the two spouses by definition, how can the non-baptized spouse possibly be receiving that sacrament?
The Catechism of the Catholic Church (CCC 1213) and the Code of Canon Law (c.
849) both use the same language—baptism is the doorway (ianua in Latin) to the other sacraments. Thomas Aquinas used precisely the same phrase in his Summa Theologiae (III q. (See “Inclusive Language and Baptismal Validity” for a different but related discussion of this basic issue.) This means, obviously, that if a person who has never been baptized attempts to receive another sacrament—like confession or matrimony—he can’t.
Q: An unbaptized person can’t receive any of the other sacraments unless he gets baptized first, right?
So how is it possible for a Catholic to marry a non-Christian in a Catholic ceremony?
Instead, the relevant canons of the code repeatedly assert that the cleric simply “assists” at the marriage (cc. When a Catholic marries an unbaptized person, even in a Catholic ceremony, the Catholic spouse is not conferring the sacrament of matrimony on the non-Christian spouse.
And the Church does not hold that the non-Christian confers the sacrament of matrimony on the Catholic spouse either.
As canon 1057.1 observes, a marriage is brought into being by the lawfully manifested consent of two people who are legally capable of getting married.
In other words, the Catholic cleric, who must be present at a Catholic wedding (with some rare exceptions that do not concern us here), does not actually marry the two spouses, because they marry each other.
Nevertheless, as the Second Vatican Council’s Document on Religious Freedom Dignitatis Humanae stated unequivocally, This Vatican Council declares that the human person has a right to religious freedom.
This freedom means that all men are to be immune from coercion…
in such wise that no one is to be forced to act in a manner contrary to his own beliefs… Within the context of marriage, this means that the Catholic Church will not—because it cannot—claim that you can only get married if you are a Catholic, or only if you’re a baptized Christian.