There is so much that separates them. History. Religion. Politics. Culture. Violence. But for almost three weeks, 39 teenagers are trying to become their own community, citizens in the Gary and Jerri-Ann Jacobs International Teen Leadership Institute, known as JITLI (jit-lee) for short. Among them: 10 Israeli Jews from Sha’ar HaNegev, next to the border of Gaza; 10 Bedouin Muslims,…