Leviticus 19:33-34 tells the people of Israel, "When foreigners reside among you in your land, do not mistreat them. The foreigners residing among you must be treated as your native-born. Love them as yourself, for you were foreigners in Egypt. I am the Lord your God."
We are God's adopted children, adopted into a family history that includes a litany of exiles, immigrants and outsiders. From Abraham, to Ruth, to Paul traveling the Mediterranean.
Much damage has been done in equating one's nation with God's chosen people in the Bible. The interpretations do not work for a variety of reasons. But we as Christians believe that much of what God commanded of Israel as the chosen people applies to the Church, the body of Christ. And so we cannot ignore the call to "love the foreigner as yourself". We are supposed to know what it is like to live in a world where we do not fit in, where we do not belong.
God had given Israel the promised land as a mighty gift. It was their inheritance and their lifeblood. Do you think they welcomed the intrusion of foreigners? They would have seen an influx of immigrants as a threat - not only to their way of life and livelihood, but the very foundations of their faith. Why should we tolerate your presence? God gave US this land. It is OURS!
And yet God commands them to remember - you were exiles once. And in that he reminds them of something even more fundamental - Do not forget that I am the one who gave you this land. It is mine now and forever, just as you are mine, just as the resident alien is mine. Treat them accordingly.