I see mention of the fact that one can ‘resign’ one’s membership from the Roman Catholic Church. I’m not sure how that works nor how it affects a person who later wants to be restored. Hence the following hypothetical tale:
A Catholic woman has four kids. All are baptised and confirmed; however Mom is not an especially ardent Catholic and the kids are not given strong upbringings in their faith. By the time they are all young adults, all are inactive Catholics. Three of the kids formally resign from the Church, actually sending formal letters of resignation to their priest and/or bishop announcing they are no longer Roman Catholic.
One of these joins a Buddhist sect and spends years in a non-Christian religion.
One becomes an ardent atheist.
One suffered some sort of real and serious hurt in the Church and resigns out of bitterness and a desire for self-protection.
The fourth child does NOT formally resign from the Church but drifts away. They simply don’t go to Church or practice their faith.
Meanwhile, as Mom waxes older, she finds faith and a zeal that she lacked while raising her kids. She prays and ministers to her children for years, and gradually softens their hearts to the Church. After her death the siblings spend a year contemplating all that Mom has said and done to appeal to them. On the Saturday before the anniversary of her death, the siblings resolve together to return to the RCC. They each dig out their baptismal and confirmation certificates and proceed to the local Catholic parish, where each presents themselves for Confession. They make it known that they wish to be absolved of their sins and restored to full communion with the RCC so that they can honor their mother on the following Sunday morning by receiving communion together as a family.
Obviously, the sibling who never resigned from the RCC but merely drifted away for long years can be restored to full communion forthwith–assuming no other impediments to absolution. What about the other three siblings–again, assuming there are no other impediments to their situation AND assuming the priest accepts the sincerity of their repentance and confessions?
Don’t baptism and confirmation in a Catholic Church automatically make one a Catholic forever, so long as one duly repents of all mortal sins?