You don't actually have to reject God, though. Merely being skeptical earns the same punishment as a murderer or a rapist.
Wrong. Questioning or being skeptical are not damnable sins. Letting your questioning or skepticism separate you from him is where the problem lies. Even murderers and rapist can repent and receive salvation if they are true in their hearts. It's not actions it's faith, and true faith makes you strive to stop the bad actions and live as a proper example. It's really quite simple.