Can Unconfessed sins destroy the Soul?

Which is worse to take a crime and hide it from the world or to confess it openly unto the world and take the consequences good or bad? Does the guilt eat away at you and you eventually tell anyway or not? If so why tell to begin with? In the opinion of the author, I think that it is worse to take internal punishment than external because external eventually will deteriorate, unlike internal that will stay hidden with you until your grave unless you break down so much it is no longer to hide you secret any longer.
My theory is supported in a very good example that takes place in The Scarle…