I’m talking about venial sins. For example. If one grew up in a culture where abortion was considered a simply procedure much like removing a wart and thought nothing wrong in having one. Their parents got abortions their siblings all got abortions it was common every day occurrence in their culture for 100 of years. Would they have committed a sin if they get one? I agree they would have committed a great evil, but is it a personal sin they would need to repent of? Especially if after somebody explained to them the great evil of abortion and they agreed and never had another one. Would they need to confess the abortion prior to knowing it was a great evil?
Another example. As a former Protestant I presumed upon God to know for sure I was going to be united forever to Christ and participate in the beatific vision. I believe all my future sins where forgiven because I said the “sinners prayer”. But once I came to the Catholic faith I understood this was a grave error prideful error on my part. Was I sinning in this belief?