Well, what about it? Who IS my neighbor? A lawyer asked Jesus that question once. Jesus had just told him to love thy neighbor as thyself, but for a lawyer, that answer isn't good enough. "Okay," we can hear him reasoning, "if I am to love my neighbor, then I needn't love someone who is not my neighbor." Hence the question, "Who is my neighbor?"
Jesus gave him an answer in the form of a parable (Luke 10:30-35 NKJV): "A certain man went down from Jerusalem to Jericho, and fell among thieves, who stripped him of his clothing, wounded him, and departed, leaving him half dead. Now by chance a certain priest came down that road. And when he saw him, he passed by on the other side. Likewise a Levite, when he arrived at the place, came and looked, and passed by on the other side. But a certain Samaritan, as he journeyed, came where he was. And when he saw him, he had compassion. So he went to him and bandaged his wounds, pouring on oil and wine; and he set him on his own animal, brought him to an inn, and took care of him. On the next day, when he departed, he took out two denarii, gave them to the innkeeper, and said to him, 'Take care of him; and whatever more you spend, when I come again, I will repay you.'"
Then Jesus asked a most interesting of questions: "So which of these three do you think was neighbor to him who fell among the thieves?" (v 36)
By asking this, Jesus was refusing to answer the lawyer's question, for the lawyer's question missed the whole point. To Jesus the issue is not "who is my neighbor", but rather "be a neighbor".
"Who was neighbor to him who fell among the thieves?" It was the Samaritan, whom any self-respecting Jew of the day would despise. Yet Jesus used him as a model. For our job is to be good neighbor rather than deciding whom our neighbor should be.