Is Leaving The Catholic Church A Sin?

Up until 2010, Catholics could apply to formally defect from the Catholic Church. They had to send in a formal act of defection to the bishop of their baptismal diocese.  

A note would then be made in your baptism register, noting your desire to leave the church. 

Today, the only way to leave the Church is through public/notorious defection. 

What does it mean for your soul when you leave the Catholic Church? Are you committing a sin, or worse, an unforgivable sin? Are you still a Catholic even when you leave? Can you be accepted back?

We answer all these questions below. 

Is it a Sin to Leave the Catholic Church?

Yes, it is considered a sin to defect from the Catholic Church. And it’s not merely a sin against the Church, but against God. 

You are rejecting God’s salvation, which can only be found within the body of Christ, which is the Church. You are also rejecting God’s law and grace. 

If you remember your Catholic teachings, rejecting God’s salvation and Grace is clearly a mortal sin. Worse, it’s the unforgivable sin mentioned in Matthew 12:31.

And so I tell you, every kind of sin and slander can be forgiven, but blasphemy against the Spirit will not be forgiven.

Rejection of salvation is regarded as blasphemy against the Holy Spirit, which only ends in eternal damnation. 

Don’t forget that you’d be missing out on sacraments essential to your salvation and relationship with God. These include the Eucharist, and confession. 

Is Joining a Protestant Church a Sin?

It doesn’t matter whether you are leaving the Catholic Church to become an atheist, or join a protestant church. It’s still an act of defection from the church, and that’s a sin. 

It’s more than a sin; it’s a mortal and unforgivable sin. 

I’m I Still Catholic If I Defect from the Church?

If you received a Catholic baptism, then the Church considers you a Catholic for life even when you leave. You are just not a part of the church. 

Baptism puts a permanent mark of Christ on you, and thus cannot be repealed. Here’s what the Church officially states. 

It remains clear, in any event, that the sacramental bond of belonging to the Body of Christ that is the Church,  conferred by the baptismal character, is an ontological and permanent bond which is not lost  by reason of any act or fact of defection.

Can I Rejoin the Catholic Church After Defecting?

The church is always open to everyone who wishes to join. That includes defectors. 

There are no official rules on the procedure of re-entering the Catholic Church after defection. So we recommend talking to your bishop for guidance. 

They’ll most likely assess if you are ready to become a member of the Church again. You’ll also have to go to confession to seek forgiveness for your mortal sin. 

Note that you don’t have to be baptized again if you were already baptized. Baptism happens just once, then it’s permanent. 

All that will happen is that the diocese will amend your baptism entry to note that you’ve rejoined the church. 

After the bishop accepts your request to come back and you fulfill all necessary requirements (such as confession), you’ll be once more eligible for sacraments such as communion.

Ready to learn more? Here is our latest article about the vocations of the Catholic Church, and also this one about donating your organs to science.