I'm not a right-wing "US government is conspiring with UN to set up concentration camps" nutcase, but the amount of incorrect claims in your post is so staggering that I have to play the devil's advocate here.
What a load of bullshit. The government isn't supposed to fear us, you twit
A democratic government of free people is not supposed to fear those people, you're right. However, is that governments can sometimes devolve from democracy into a populist tyranny of the majority, and ultimately into a dictatorship. Nazi Germany was an extreme example of that; more mild recent ones are Russia and Venezuela. The point is that any people in the government who have similar notions should be fearful of an armed and vigilant populace.
Several times since the Revolutionary War, nutcases have tried to rise up in armed resistance to the U.S. government. The largest such rebellion took place between 1861 and 1865.
So Civil War was just a bunch of nutcases rising up in armed resistance against U.S. government, really? And not, say, duly elected governments of several states, which at that time considered themselves sovereign, seceding and establishing their own government?
Regardless of the unsavory causes for the sake of which CSA was established, it is as far from what you're trying to portray here as can possibly be. It was an example of two professional, state-funded and state-controlled armies hashing it out in the field, not unorganized militia.
. If someone burns down my house or murders someone in my family, I don't want the government to be afraid to arrest and prosecute the guy who did it
Hypothetically speaking, what if the government burns down your house and murders someone in your family?
TL;DR version: your entire argument hinges on the notion that government is always beneficial. This is provably not the case: USSR, Nazi Germany, DPRK are all examples of extremely oppressive governments. There are also numerous examples of benign governments which devolved into oppressive ones, either through abuse of populism in times of crisis, or through an internal coup d'etat. The "security of a free state" argument is about preventing that from happening, not about resisting a legitimate democratic government.