Promises Reflection

In the Promises Movie, there are kids from different religions. Both think terrible things about each other. They say the same things about each other, yet both of them are nice. If there was not that war, all those kids would be best friends. I like the way the kids were acting when the main person were on the other religion. Why can not everyone be friends and just stop the war? Why? Why can not we just help bring them together? Can we just at least raise money to help them build more bomb shelters or farms, or houses?