Guilt is a method we use to cause harm to ourselves. For instance if you were abused as a child and today beat yourself up with guilt over things you've done in the past, you have continued the pattern of abuse. Guilt has no purpose!!! If you refuse to accept guilt in your life, there will be no need for punishment. The abuse cycle is then broken.
This also means we won't be pointing fingers at others either. Instead we take responsibility for our part in every situation. We forgive those who have caused us harm just as we forgive ourselves for the things we've done to cause harm.
Don't give power to guilt. Let the past go. And if you make a mistake in the future, merely correct it without giving any power to judgment over it.