Humans are by nature considered to be nasty,brutish and short term(Leviathan). This is probably due to their ability to take free and rational choices. They are characterised by their ability to control their own destiny making them responsible for their own actions whether it be good or bad.
Individuals could do anything without limitations such as smoking, drinking to death, may spend every single day watching tv or looking at pornography, blaspheme, commit suicide, deny the existence of God, engage in any form of consensual sexual unorthodoxy.
Thereby making them the species with the high level of freedom.
But an issue tends to arise when individuals use their freedom excessively in a manner that would affect the freedom and autonomy of the other people around them.
This causes people to live with fear, therefore the reason we have to live with fear is due to our own doing.