As an outsider, I don’t understand how to “confess”. Since the definition of sin changes every few years, how does one know what he did that was wrong?
There was a time when major commerce was conducted on Sunday. That was when rurual people walked to town on Sunday to sell their produce and attended church.
Then, there were decades when it was a sin to do commerce on Sunday. Laws against it were called Blue Laws. Homosexual relations have been sin for several lifetimes but the majority probably don’t regard it as sin today.
Catholics aren’t the only ones to have a ceremony to humble people. Jews have a once a year event of humbling themselves to people they have wronged during the year.
I once participated in a Native American sweat lodge ceremony. As I recall, there were three phases to that ceremony, all having to do with correcting relationships with other people. (I have to confess I was gasping to breath from the steam and heat I can’t remember too much.)
Atheists mostly find the concept of sin to be one invented by ancient groups wanting to control others. Those in control wanted certain behavior so they labeled nonconforming behavior as sin. The only way to unload sin was through those with authority. Thus, if an atheist went to Catholic confession, he would have nothing to confess.
All the atheists I know want to be good people and good citizens. So far, confession has not been needed.