It stands to reason that if nobody disagree about anything conflicts would not arise.
Except that's not the case at all. Of course conflicts can arise. As long as the majority recognizes that private property is the foundation of a peaceful society, they will be resistant to those who disagree and try to cause conflicts. But conflicts between private property owners will happen all the time. That's why we have laws and courts: to sort out violations of contracts.
It's a very fragile equilibrium to maintain though. Other private property owners may have the incentive to recognize your private property so their own is preserved too, but that incentive diminishes as the wealth inequality increases.
In a way it's fragile because it is so vulnerable to an ideological shift to collectivist systems like socialism and fascism, but in a way is it also very strong, because it is the powerful force that enriched all humanity and still does.
The idea that wealth inequality should be a divisive force in society is a heinous lie told by socialists to stir up revolution. First of all, wealth is NOT money. It is more accurate to equate wealth with your standard of living, and by literally ALL accounts, the standard of living of the poorest among us today is hundreds of times better than the poorest were just a century ago. Just a century ago, about 70% the global population was living in poverty (described as less than $1/day); today the rate is less than 20% even while so called "wealth inequality" has increased.
Second, wealth comes from contribution to society and some people will contribute FAR more to the betterment of humanity on this earth than others. The goal should not be to ensure everyone gets an equal share of this wealth, but to maximize the rate at which this wealth is generated. One of the best examples of this is the washing machine. Before the washing machine, washing clothes was a back-breaking task that took 2 or 3 days every week. If you were wealthy enough, you could hire someone to do it for you, but everyone wears clothes so every family had to do it.
The invention of the washing machine took billions of people from that lower level of wealth, to the same level of wealth as those people that could hire someone to do all their washing. Consider all the free time people gained by the act of washing going from 2 to 3 days per week down to about an hour per week... THAT IS WEALTH. Can you imagine denominating all that free time just gifted to humans in dollars? I hope the inventor of the washing machine became a multi-billionaire for that contribution to the wealth of everyone!
Also think about this: how do parents educate the children to the rules of that society without coercing them in some way when they violate those rules?
Parenting is an entirely different can of worms that I'm not going to pretend I know anything concrete about. One thing's for sure, everyone has a theory about the right way to raise a child until they actually have children.