Forgiveness means getting a chance to change your behaviour and stop doing it. If you are still alive, you can have it, if you become steadfastly determined to change.
It's necessary because even the most wise still have a little stumble here and there, but so long as it is only thought and does not lead to action, it is not a sin. Dwelling on the thoughts does make it tend to become an action, so casting it from your mind is part of the work.
But most people do commit these sins. What justifies our forgiveness? We kill, we commit adultery, we steal. We're not inherently evil, but we're not inherently good either.
I'm sorry if these questions sound stupid in any way.
I just don't understand religion. I'm trying!
Sin is just making mistakes, either by accident, or with intent to profit. Of course we cannot avoid it entirely. But what use is there in not forgiving yourself, at minimum? Since this is an error, it is a sin. It is an error to not attend to the present moment, and dwelling on and repeatedly punishing yourself is also an error.
We are justified by faith.
