Never underestimate the individual potential for evil and the collective certainty of it. Groups are very likely to be evil. View their approach armed and ready for anything. But always remember that you can resist evil without becoming evil.
History shows that if you want to be peaceful you have to back it up with viciousness in the face of attack. This is completely in accordance with the Zero Aggression Principle. And you have to keep and bear, or in more modern terms, own and carry, the tools to keep invaders (who are just another aggressor) from prevailing.
But you may believe your society is "safe". You may say that things like that don't happen where you live. "Not here. Not now." Are you willing to bet your life, and the lives of your children, on that? It isn't enough to feel safe. Even if you are, the situation can change overnight and then it's too late to get the tools and learn to defend yourself.
None of this justifies stealing from your neighbors or coercing them in any way to form a State or a State military. If you have to become the bad guys in order to survive, your survival isn't worth much. You can't preserve your liberty by destroying it.