Is A World Free of Violence Possible?

They would believe that was the case until they change their mind and decide their neighbor deserves to be punished for something vile ( like letting the grass get long)

Some are killers.

If all people chose to live by this principle, we would have a wonderful, peaceful and productive world; a 'Paradise" if you will.
"Do unto others as you would have them do unto you" is another good one. Results would be similar, I think.

I have been fortunate to have visited the ten most peaceful countries in the world. Unfortunately, our country is not one of them.
http://www.forbes.com/pictures/eedh45fkjmf/no-10-czech-republic/#76f53b682039

Awesome. I would like to travel someday.

No.

So, do you think that humans can be peaceful without an all-powerful Lord ruling over them?

I can only answer philosophically, Max.
And that means switching off my emotions.
People don't like that on this site.

Firstly - Your interpretation of 'peace' is different to mine and everyone elses'.
Some find solace in chaos - Some find solace in drugs, alcohol, sex, perversion, pain, promiscuity, etc.
"PEACE" is a label.
So - How does one aspire to something when it it undefinable?

Is it peaceful for a grazing antelope when the lions slumber?
Is it peaceful for the lions when the antelope is slow and the meal is granted quickly?

Sadly that is true. Fortunately most are not.

Why should I believe in the existence of a supernatural celestial dictator without one iota of evidence to suggest it’s any more likely than unicorns, tooth fairies, and ghosts? Further, the golden rule existed far before all your Abrahamic mystical mumbojumbo.

Arthur C. Clarke beat you to it in 1953 with Childhood's End.

Tell em the facts, Chumly. But it won't help. I should know. My siblings are christians, and believe in the tooth fairy. OOPS, I mean the god in the sky.

Yes its possible. When all of us are turned to robots.

Yes or No, depends on free will. Nothing is fated. If people will follow their conscience, we can have a beautiful world.