Catholics switching to Protestant

From this do I understand correctly that a Catholic can indeed leave the faith for a Protestant one and even the Church would not consider it mortal sin if the person is sincerely convinced that they’re making a decision based on truth as he or she understands it?

That appears to be what it says. The key is in what makes sin “mortal sin”. It’s not just that grave matter is involved; it also involves full knowledge, and full consent of the will.

Also what’s the difference between looking for a church that suits them vs someone making a decision based on their understanding? If someone looks for a church that suits them, it seems to me what suits them can be based on their understanding of God.

I know but couldn’t one have full knowledge and understanding of what the Church teaches but simply still not in good conscience believe some of the teachings? Informing the conscience is one thing but forcing it to be something it is not is another. So they willfully leave the faith rather than follow things they don’t believe.

The Church does not consider ANY act mortally sinful, by the nature of the act alone.

CCC 1857 For a sin to be mortal, three conditions must together be met: “Mortal sin is sin whose object is grave matter and which is also committed with full knowledge and deliberate consent.”

The act itself is only 1/3 of the equation. Killing somebody might be mortally sinful, or not EVEN sinful. A Catholic may kill somebody, and it could be a mortal sin (so he is no longer in a State of Grace), or a Catholic could kill somebody and it is not EVEN a venial sin (so he remains in a State of Grace, without even attending Sacramental Confession).

SOME Catholics have renounced the Faith, and it is difficult to imagine that THEY had imperfectly formed knowledge and consent. Martin Luther is the obvious example - he was a Catholic Augustinian priest.

Deliberately leaving Christ’s Church is objectively very gravely sinful. However, mortal sin requires full knowledge and complete consent, which can only be known to God.

The Catechism on mortal sin:

1857 For a sin to be mortal, three conditions must together be met: "Mortal sin is sin whose object is grave matter and which is also committed with full knowledge and deliberate consent."131

1858 Grave matter is specified by the Ten Commandments, corresponding to the answer of Jesus to the rich young man: "Do not kill, Do not commit adultery, Do not steal, Do not bear false witness, Do not defraud, Honor your father and your mother."132 The gravity of sins is more or less great: murder is graver than theft. One must also take into account who is wronged: violence against parents is in itself graver than violence against a stranger.

1859 Mortal sin requires full knowledge and complete consent. It presupposes knowledge of the sinful character of the act, of its opposition to God’s law. It also implies a consent sufficiently deliberate to be a personal choice. Feigned ignorance and hardness of heart133 do not diminish, but rather increase, the voluntary character of a sin.

1860 Unintentional ignorance can diminish or even remove the imputability of a grave offense. But no one is deemed to be ignorant of the principles of the moral law, which are written in the conscience of every man. The promptings of feelings and passions can also diminish the voluntary and free character of the offense, as can external pressures or pathological disorders. Sin committed through malice, by deliberate choice of evil, is the gravest.

1861 Mortal sin is a radical possibility of human freedom, as is love itself. It results in the loss of charity and the privation of sanctifying grace, that is, of the state of grace. If it is not redeemed by repentance and God’s forgiveness, it causes exclusion from Christ’s kingdom and the eternal death of hell, for our freedom has the power to make choices for ever, with no turning back. However, although we can judge that an act is in itself a grave offense, we must entrust judgment of persons to the justice and mercy of God.

Here is a selection of papal quotes. Notice the importance placed on being in communion with the Pope.

“The Church is One, Holy, Catholic, Apostolic, and Roman: unique, the Chair founded on Peter … Outside her fold is to be found neither the true faith nor eternal salvation, for it is impossible to have God for a Father if one has not the Church for a Mother.”

-Ven. Pope Pius IX

“If any man be outside the Church, he will be excluded from the number of sons, and will not have God for Father since he has not the Church for Mother.”

-Pope Leo XII

“Consider, therefore, that whoever is not in the peace and unity of the Church cannot have God.”

-Pope Pelagius II

“This Church, thus marvelously founded, assuredly could not cease with the death of its Founder, nor of the Apostles who led the way in its propagation, for to it the commission was given of bringing all men to eternal salvation: all men, without distinction of time or place …** Now, no one is in this One Church, and no one perseveres in it unless he acknowledges and obediently accepts the power and authority of Peter and his legitimate successors.**”

-Pope Pius XI

“He Who reigns on high, to Whom is given all power in Heaven and on earth, has entrusted His Holy Catholic and Apostolic Church, outside which there is no salvation, to one person on earth alone, namely: to Peter, the Prince of the Apostles, and to Peter’s successor, the Roman Pontiff, to be governed by him with the fullness of power.”

-Pope St. Pius V

“Neither sanctity nor salvation can be found outside the Holy, Catholic, Apostolic, Roman Church.”

-Ven. Pope Pius IX

“Before everything else, fidelity to the Church: One, Holy, Catholic, and Apostolic. Jesus did not found several churches, but one single Church.”

-Pope St. John XXIII

As a sacrament of intimate union with God, the Church is in Christ, outside Whom there is no salvation.
-Pope St. John Paul II

“He who is separated from the Catholic Church will not have life.”

-Pope Gregory XVI

“It is a sin to believe that there is salvation outside the Catholic Church!”

-Ven. Pope Pius IX

Most decisions like this aren’t made in an abstract vacuum. Someone gets divorced, wants to get remarried, but still wants some Christian connection. So they find a church that is compatible - or better, encouraging, nourishing, spiritual, with what they want to do. They adapt their theology thus, throw in a lot of words about “compassion for persons”, “follow your heart not your dogmas” etc.

Or they have a son who wants a gay wedding. They rationalize "I want to continue my role as a parent, and want my son to continue a Christian connection. So now my good *conscience *is telling me I will not be a “fallen-away Catholic” but rather (I just noticed) that the Catholic Church is “unloving” in this matter. I am choosing the Episcopal Church as more consistent with my sincere theological beliefs.

I want to be accepted as a caring, up to date social worker. But in this field the “trend” is to be pro choice. It causes me stress to profess one thing in church, and another thing in my profession. So if, in good conscience I can come to the prochoice view, including on Sunday, I will be at peace spiritually.

None of these decisions was based on using their God-given power of reasoning. After they make their decision, they will go on to “discover” more problems with Catholicism be rigid, cold, unloving, etc to make themselves more comfortable with their decision. When people say my “good conscience” they may mean my anesthetized conscience.

That’s a relief. This has been a source of much conflict in our family. So it’s OK if our daughter converts to her boyfriends Calvary Christian Church if she sincerely feels drawn to that spirituality?

No it is not OK. This is a grave matter. Your daughter is putting her salvation in jeopardy by doing so. Having a poorly formed conscience / keeping oneself in ignorance does not excuse one from culpability. She has the obligation to do everything in her power - including talking with a holy priest (as many times as it takes), and researching and reading about the authentic position of the Church on this most important matter (synthesizing (but NOT disregarding) the entirety of Catholic Tradition with the pastoral suggestions of the post-Vatican II Church). She should also pray, particularly to the Blessed Virgin, to help her in this trial. Only after she has done all of this and has formed her conscience in truth and sincerity, should she approach the question of whether or not she truly wishes to leave the Holy Roman Catholic Church. This is the most important decision she will ever make, and it is truly a matter of life and death.

No, it’s not “OK.” Leaving the Catholic church for a protestant one is still objectively gravely sinful. You should still point this out to her and let your concerns be known. You just can’t assume that she’s automatically separated from God’s grace.

Please note that “leaving the Church” is different than “leaving the faith”, (or ‘rejecting the faith’). The Church is indeed an integral part of the Faith, but it is not itself, “the Faith”.

Hence one could leave the Church–by ceasing to attend mass for instance, and instead, attending Protestant services (for example) out of consideration of/for family harmony…without rejecting any fundamental tenet of the Faith.

Conversely, one can reject fundamental tenets of the Faith–e.g.–believe that the Eucharist is just symbolic bread and wine (and partaking of it); or have had an abortion, and justify it as a matter of choice, and not a sin (and therefore not confessing it as such)…and attend Mass regularly. That, imo, would constitute a rejection of the Faith–while, outwardly, hypocritically, pretending to remain in the Church–or in communion with the Church.

The latter, imo, would most likely constitute mortal sin, while I don’t believe the former scenario would.

Sadly, that latter, and far more egregious scenario, is far more common than most of us would ever care to admit.


I don’t believe that’s what he said. He simply said that no act, in and of itself, alone, isolated in a vacuum, constitutes a moral sin, as the ACT alone, only constitutes 1/3 of the analysis.


You should point out to her that there is no such thing as an ex or former Catholic. Anyone who is baptised a Catholic remains a Catholic forever, even if they walk away from the Church.
Once a Catholic there are only two types of Catholic - those in a state of grace and those in a state of mortal sin.

It is absolutely not okay to walk away from the Church.

If I might turn it around, why is it strange that we believe that?

What Protestant denominations do you know that state “Becoming Catholic is a sin, even for someone who is sincerely convinced that they’re making a decision based on truth as he or she understands it”?

Yeah, that’s what I said.

People come here and ask, “is so-and-so a mortal sin?” And the answer is always the same (no matter what so-and-so is). The answer is, “maybe.”

That only means that it MIGHT not be mortally sinful to leave the Church. It certainly COULD be mortally sinful. It is a very serious thing to do and would usually be a very deliberative act (not something done rashly), which raises the probability of being a mortal offense.

If that is the case, then there are an awful lot of mushy, ambiguous, unclear and imprecise posts on the subject in this thread.

Let’s just leave it at “It is absolutely not okay to walk away from the Catholic Church !”

I am assuming that whoever writes an opinion on this thread is “educated” and this is a blessing from God. The question is not so much as switching to Protestant as it is not using one’s blessing (education) from God to search for the truth before switching. The problem is that majority of Catholics, Protestants, Moslems, Jehovah Witness, Mormons, Atheists, etc. etc. do not know their faith and do not put in much effort in finding out the truth about what they believe. In switching from one faith to the other, did you make an honest, sincere effort to compare the two faiths before switching or are you switching because one is more convenient. Being sincere is not enough; you can be sincere but sincerely wrong. The 9-11 bombers died for their belief; they were sincere but boy were they wrong.

In addition to being sincere, one has to be open-minded and use one’s blessings in the quest for the truth before switching one’s faith. There has to be a comparison between the faith one is switching from and the faith one is switching to.

For the majority of humans who are not “educated”, God provides them a way, through us who are “educated”, to find the truth. Therefore, we “educated” ones have a responsibility to God to seek the truth and use it to educate the “uneducated”.

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