One should not act in an arbitrary manner with limitless ego. Everybody should enquire, "If I do this, what will happen? Whether I should do it or not?"
You have to reap the consequences of your actions, if not today, at least tomorrow. You may think that God has forgiven you for your sins, but you will have to suffer the consequences of your actions, some time or the other.
It is also possible that all your evil deeds may come to you, all at once. If you want society to progress and prosper, you should always keep the welfare of the society in your view