how can you give someone an authority you do not have yourself? you didn't answer the question.I'll take a stab at it. People in general grant government authority over them and become subject to its laws, imperfect as government may be, in order to help keep chaos at bay and have an ordered and civilized society with common rules. Government then authorizes its police to enforce those laws.
Not everyone is happy with that arrangement, but it is what it is. Government of some type will always exist as long as people exist on this earth.