We then separate ourselves even further by adhering to different religions, "races," and traditions. It's as if we are all searching for an identity that we had and threw away. There really aren't any countries - we invented them. The same holds true for race - we all evolved out of Africa. Our physical differences are merely adaptations to the climates we settled in. Religions are so varied that there are thousands of them - including divisions of our major ones. They were, partially, conceived so that we could have laws and rules. But...have now grown into large entities that fight to hold onto our minds.
How did we stray from the oneness of "us?" We let ourselves. However, the beauty of it is that we can get that oneness back. It just takes the ability to realize it, believe it and live it. That's all!
So...while we can celebrate our global diversity, we should think twice about making any of it separate us. Our celebrations shouldn't become exclusive - but, we've managed to do that in a lot of cases. Instead...let's celebrate "The Wonder of the Oneness of People." I think that would make for a wonderful holiday!