In USA, we live side by side peacefully. I mostly lived and worked in more diverse areas, so I can tell you at every workplace you'll find Christians, Jews, Muslims, and people from other religions or people with no religion. Same for ethnic backgrounds, we all co-exist. We live, work, shop, socialize side by side with no problems. We see we're all the same, just wanting to go along with our lives, see our kids grow up and have a future.
I have all types of friends Jews, Christians, atheists, Muslims (of course as someone from Muslim background), Blacks, Latinos, Asians, LGBTQ members. I love, appreciate and trust some members of the 'other groups' more than some members of my own 'in group'.
Of course, we see polarization in USA being install in recent years that creates division between groups for political reasons. Very much the same, how division is inflicted in the Middle East, for political reasons, for power. When this intentional division is inflicted, we argue and hate each other maybe, call each other names childishly but we keep functioning as a society altogether, side by side because nobody forces up to fight with each other (and hopefully will never). In Middle East, when intentional division is inflicted, usually it is part of a plan where world powers are looking to sustain their power or increase their power.
The root cause is not the people who can not live side by side despite differences, it's the ones who inflict this division for their benefit. So, no we don't need to be divided into further borders defined by religion or ethnicity. We just need to realize that we should say no to the ones who want to divide us.
Sorry for the long rant. But it feels very hypocritical when the same powers who pushes diversity for the many countries but claim that same diversity can not co-exist when it comes to Middle East despite its long history of co-existing together for thousands of years.