Utopia is impossible. There are far too many problems. Liberty vs Security, wealth and prosperity vs a finite resource supply, Individual Ambition vs Alturistic Needs and of course Knoweldge vs Ignorance.
Utopia would have to be free of crime, which either requires a total change in human nature from what we've been doing for the past 50 000 years (just over 5000 if you're jewish) or a massive increase in oversight and control. Which in turn creates conflict, and we're back to where we started. I suspsect nothing short of actual mind control would be enough to ensure
safety and security on that scale. A morally reprehensible action that eliminates our individuality, so basically pointless and against the very principle of utopia.
It would also be free of poverty, which would either require us to remove a large chunk of the population, or settle for a lot less than we have now (especially true in the west). We simply do not have the resources to treat everyone equal if we maintain western living standards with the current population size. And how do you ensure the alturistic spirit continues? You can't, unless you use mindcontrol, in which case liberties suffer and our "utopia" is basically just a machine with no free thoughts, no creativity, no change and no "life". Which is anything but a Utopia.
And of course you have the age old problem, what do you do when people are just too stupid to learn or simply refuse to? Racism is a product by ignorance, as is xenophobia, as is anti-nationalism (in most cases), and a lot of other feelings of misstrust and hatred that prevent any sort of "harmony" between the two. Forcing them to agree is also out of the question.
Utopia would also be technologically advanced, and in my opinion, cultivate knowledge, creativity and advancement. Naturally there are other people who might see utopia as a religious institution controlled by certain rules and religious dogma. So getting people to "play on the same team" would be difficult enough. How do you cultivate advancement, knowledge and creativity in a society that attempts "perfection" where everyone is in agreement about how things should be run and exist? You can't. Advancement can only be achieved through challenging old ideas. As a result there will be conflict. Without conflict you are at a standstill. Sounds boring.
You can never make everyone agree on anything. Heck I'm even positive people disagree with me on that.