A lapsed Catholic is a person baptised as a Catholic who is non-practising. Such a person may still identify as a Catholic and remains a Catholic in the eyes of the Church. The term is neither formal nor well-defined; there is a range of degrees of separation from fully practising Catholic, to lapsed but in generally good standing, to excommunicated heretic. Lapsing is a failure to follow observances and is unrelated to belief.
Catholic teaching 
According to Catholic belief, baptism "seals the Christian with the indelible spiritual mark of belonging to Christ. No sin can erase this mark, even if sin prevents Baptism from bearing the fruits of salvation."
Lapsing from the Catholic faith is less serious than rejecting it. Rejection is more than failing to practise the faith; it involves professing to believe something contrary to the faith, or joining a sect or group that does not profess the Catholic faith. Such rejection can be done without joining another religion. The Catholic Church distinguishes sharply between someone who has ceased to practice or who privately has stopped believing the Church's teaching, and someone who notoriously, i.e. consciously and publicly, rejects the faith, considered very serious—for example, the Church may refuse to marry such people without the same promises required by spouses in mixed marriages.
From 1983 a more grave formal act of defection from the Catholic Church was recognised in the Code of Canon Law, making defectors ineligible for the privileges of membership of the Church, such as marrying in church. This form of defection was removed from the code in 2009, and it was no longer possible to defect formally from the Catholic Church.
Even the further form of censure known as excommunication does not make a person an ex-Catholic; they are still subject to the same religious obligations, but their communion with the Church is considered impaired.
In medieval times non-Christians (in particular many Jews and Muslims) were forced in Christian countries, particularly Spain, to convert to Christianity (Catholicism). Children were also sometimes forcibly baptised; this was considered to save them from damnation. A baptised person not being seen to act as a good Catholic could lead to an accusation of crypto-Judaism—heretical behaviour by a Catholic. Denunciation, not necessarily supported by evidence, of anybody for what would now be considered lapses such as not fasting on Fridays, absence from Mass, working on Sundays or compelling servants to work on feast days could lead to torture by the Catholic Spanish Inquisition and execution by the state.
Colloquial names 
Some lapsed Catholics attend Mass on special occasions like Christmas and Easter. Such lapsed Catholics are colloquially referred to by such terms as Cultural Catholics, Two-Timers, Chreasters, C&E Catholics, Poinsettia & Lily Catholics, CEOs (Christmas and Easter Only), CAPE Catholics (Christmas, Ash [Wednesday], Palm [Sunday], Easter), PACE Catholics (Palm [Sunday], Ash [Wednesday], Christmas, Easter), CASE Catholics (Christmas and Sometimes Easter), CMEs (Christmas, Mother's Day and Easter), Christmas Bunnies, or A&P Catholics (for Ash Wednesday and Palm Sunday).
Example in literature 
"He was of the faith chiefly in the sense that the church he currently did not attend was Catholic" (Kingsley Amis, One Fat Englishman (1963), chapter 8).
See also 
- Apostasy in Christianity
- Catholic guilt
- Cafeteria Christianity
- Lapsi (Christianity)
- List of former Roman Catholics
- Recovering Catholic
- Sunday Christian
- Patricia Barbernitz (1993). Parish Ministry for Returning Catholics. Paulist Press. Retrieved 14 June 2012. ""I'm Catholic" is also the statement frequently used by some other people — those whom others might have named "inactive" Catholics, "fallen-away" or "lapsed" Catholics. For many of them, the statement remains, "I'm Catholic." It is spoken with ease, almost without thought."
- R. John Kinkel (29 September 2008). The Story of Early Christianity. Retrieved 14 June 2012. "In the old days (1950s) these people would be called backsliders, apostates, lapsed Christians, and now this label has emerged: FARC, ie fallen away Roman Catholic."
- "The Sacrament of Baptism (§1272)". Catechism of the Catholic Church. "Baptism seals the Christian with the indelible spiritual mark (character) of his belonging to Christ. No sin can erase this mark, even if sin prevents Baptism from bearing the fruits of salvation. Given once for all, Baptism cannot be repeated."
- John P. Beal, James A. Coriden, Thomas Joseph Green, New Commentary on the Code of Canon Law (Paulist Press 2002 ISBN 978-0-80914066-4), p. 1269
- Statement on Formal Defections
- "Code of Canon Law, canon 1312". Vatican.va. Retrieved 2012-04-03.
- Beit Hatsufot Museum, Haim F Ghiuzeli: Crypto Jews in Mexico during Spanish Colonial Era
- "Definition of Chreaster". Unwords.com. Nanovox Productions.
- "Don't be too quick to dismiss the "C&E Catholics" this Easter". Bearing Blog. 2007-03-06.
- "Why I hate Easter". Heart Songs. 2002-03-31.
- "Search for "Catholic priest"". Everything2.com.