It was a controversial idea for Hobbes to claim that we are all equal in the State of Nature. It means that the King and the aristocracy are no more important than anyone else. Hobbes may not have intended this, but this idea made it into Jefferson’s Declaration of Independence (“We hold these truths to be self-evident, that all men are created equal…”). The consequence of this equality, though, for Hobbes, was continual fear of one’s neighbor. You may be smart and strong, but if your neighbor convinces a few of his friends to join him, he has a good chance of killing you. Human nature, driven by competition, fear, and the desire for glory, causes man in the State of Nature to build empires. Kill or be killed.
The State of Nature is the condition one is in when there is no authority or societal laws preventing people from acting from their human nature. In this condition there is no means by which to claim morality. Nothing is unjust. The closest comparison we have is life in a civil war, or the constant threat of disaster in the Cold War. Life in the State of Nature is solitary, poor, nasty, brutish, and short.
In the State of Nature man has the luxury of pure liberty, which is the absence of external impediments on his actions, but the passions and reason encourage man to forsake the State of Nature. Fear for one’s survival leads one’s reason to find a safer life. Reason leads man to establish society.