Systematically the strong bullied the weak, and the weak did their best to persuade their persecutors, by feats of courage or endurance or by picking on someone still weaker, that they were tough and strong. The fight in the early church between the old and the new, the familiar and the strange, resident and alien, repeats itself over and over again, everywhere and everyplace. As we toured around England, visiting Cathedrals, castles and medieval manors, the history of Britain revealed itself to be the history of warfare. Every few hundred years a new people came, saw and conquered the current residents. First the Celts, then the Romans, then the Anglo-Saxon, Vikings and Normans, until the middle ages when the principal task of knights was to defend the King on the battle field and to provide soldiers, often rag tag peasants with pitchforks as weapons, to fight along side them.
English history reveals that history by and large has just been a succession of killings fields.
My theory is that we are so afraid of the newcomer, the other, the alien because we are afraid that we will be superceded. We fear becoming like an expired coupon, no longer any good. Even the early Christians wondered about God's promises that seemed now to be superceded by the emerging gentile Christian church, where non-jews were beginning to dominate. Earlier, in covenants with Noah, to Abraham and Sarah, God had yoked himself with Israel, had chosen Israel to be a holy nation, a Kingdom of priests who would witness to the world on behalf of the true and living God. I will never let you go.