Men are asocial by nature. They only move towards what they desire and away from what they fear. Their two greatest fears are death and the loss of possessions. The three main factors of discord among men are egoism, mistrust and the desire of glory.
Imagine there were no laws acting on us, no State to impose fear and force us to obey (aka State of Nature). Everyone would fight each other to death for their possessions. Under such conditions, we can't acquire wealth. We can't even assure our own safety!
But we aren't idiots. We give away our power to stomp on others in order to live in community, to guarantee our safety (Social Contract). The sum of all those powers, given away by all the people in a nation, is called State. The State must impose fear onto us so we all follow the rules. However, since this is a contract, the State must also respect the citizens.