Unity does not mean “uniform” or “un-individual”. We only have to look around us to see that we live in a vibrant, thriving, ever-changing world.
Living in harmony does not require us to agree on everything; a thriving vibrant community will be made up of members who have as many opinions as there are notes in a complicated musical chord – or orchestral score!
But we must agree on our purpose in life – to work together for G-d (or to make the world a more equitable, peaceful, and just place, if you’re not comfortable with G-d words). Our outward expression of harmony will reflect our inward harmony of purpose.
Living in unity can look like agreeing on rules for the group and boundaries that you enforce for yourself. It can also look like stepping back and allowing decisions to be made where you can see that it’s the right thing to do/decide for the community. Even if it’s not what you’d like to have happen.