why the gospel is pro immigrant
"Therefore remember that at one time you Gentiles in the flesh, called “the uncircumcision” by what is called the circumcision, which is made in the flesh by hands— remember that you were at that time separated from Christ, alienated from the commonwealth of Israel and strangers to the covenants of promise, having no hope and without God in the world. But now in Christ Jesus you who once were far off have been brought near by the blood of Christ. For he himself is our peace, who has made us both one and has broken down in his flesh the dividing wall of hostility by abolishing the law of commandments expressed in ordinances, that he might create in himself one new man in place of the two, so making peace, and might reconcile us both to God in one body through the cross, thereby killing the hostility. And he came and preached peace to you who were far off and peace to those who were near. For through him we both have access in one Spirit to the Father. So then you are no longer strangers and aliens, but you are fellow citizens with the saints and members of the household of God, built on the foundation of the apostles and prophets, Christ Jesus himself being the cornerstone, in whom the whole structure, being joined together, grows into a holy temple in the Lord. In him you also are being built together into a dwelling place for God by the Spirit."
- St Paul's letter to the Ephesians, chapter 2
This passage, following on every good evnagelical's favorite summary of the gospel, focuses in on one of the many purposes of the gospel: multi-ethnic solidarity in Christ. It's even who Jesus is - "in himself, one new man." Read through the passage again - the new man in Jesus isn't a vision of a better personal morality here. Paul does that elsewhere for sure. But in this passage, Paul zeros in very specifically on the systemic issue of laws and ordinances (policies) that exclude and harm ethnic and cultural outsiders. It was not simply a political metaphor for a "spiritual" or individual reality. Such a distinction between the political and the individual is simply absurd. Instead, the distinction is ethnic, social, and political - it's about how "gentile" and "Jew," political enemies by law and policy, are now one new humanity and brotherhood in Jesus.
And these are not just any law and ordinances, but God's own law and ordinances and all the Israelite boundaries that go along with that law. Notice that it's the religious and ethical markers of Israel that were abolished. In other words, the mosaic law was culturally and ethnically stratifying, and so it had to be made obsolete for the sake of the inclusion of aliens and immigrants to Israel's commonwealth. In other words, even though Paul views the law of God and the policies of Israel as good and holy - nevertheless he sees the effects of that law and policy as being bad - what's more, Paul says it was always the plan of God to displace the law with his Son and Spirit (Ephesians 1).
And this is not a tangential point. Paul harps on the fact that Jesus preached peace not only to the lawless (non-Israelites), but ALSO to those under God's law (Israelites). He preached peace because the mosaic law created division and hostility between those under the law and those outside the lawful community. In other words, Paul is implying that Israel wasn't justified in their lawfulness, and worse, they were all the more condemned in their self-righteous stance toward non-nationals. The gospel of peace came to neutralize this law, because under it, Israel abandoned its blessed purpose. Again and again, neither Paul (nor am I!) saying the law is bad or unholy. In fact, Paul explicitly calls the law good elsewhere. Nevertheless, Paul very clearly sees Christ as dealing with the law itself as problematic for peace.
This is plainly and directly the point: the gospel fulfilled and replaced God's own law in order to draw in the ethnic and religious outsider. Paul elsewhere says the whole mystery of the faith is revealed in the inclusion of ethnic outsiders, gentiles, nations, non-Israelites - thankfully including American evangelicals! See Romans 11, Ephesians 3, Colossians 1 - this isn't even just an implied argument - it's often the main point of Paul's mission and message. It's what makes the gospel so offensive. It's what makes the Christian faith truly translatable to any other culture and continent. The gospel breaks down ethnic barriers by condemning idealistic protectionism, and affirming ethnic inclusion in God's governance. This is the uniform witness of Hebrew and Christian scripture, that worship of the one, true God is multi-ethnic because of his reconciling work in the messiah did away with nationalistic laws and policies.
The Lord God,
who gathers the outcasts of Israel, declares,
“I will gather yet others to him
besides those already gathered.”
"And when I am lifted up all people shall be drawn to me"
The samaritans said to Jesus, "we know that this is indeed the savior of the world."
"...behold, a great multitude that no one could number, from every nation, from all tribes and peoples and languages, standing before the throne and before the Lamb, clothed in white robes, with palm branches in their hands, and crying out with a loud voice, “Salvation belongs to our God who sits on the throne, and to the Lamb!”
So what? Well, for Paul, the gospel IS the undoing of the law's boundaries, the undoing of ethnic hostility, the undoing of prejudice that other ethnicities don't belong at all or don't belong if they don't adopt our political and cultural mores. The Jerusalem council was explicit about whether gentiles needed to follow Jewish law in order to follow Jesus - the resounding answer was no (Acts 15).
From this foundation, it can be argued that the whole point of any Christian virtue or ethic isn't in personal piety or"spiritual" (read, "individual") disciplines per se, but must be a piety that embraces the ethnic and religious other as forgiven by God, even as we have been forgiven by God; and afforded the social benevolence of the people of God, even as we have been afforded the goodness of God's benevolence in all things! In short, the Christian life cannot be privatized, and is truly and vitally politicized.
I would say that the "plain reading of scripture" (cue eye-rolls) ought to lead Christians to have a simple, resolute conviction to "love immigrants, because Christ has loved you, an alien to his benevolent kingdom." God saved us, foreigners and outsiders, so our great privilege and witness in this world is to love the foreigners and outsiders, not in word only, but also in deed, not in platitudes only, but also in policy. And because the gospel of God is for the guilty and wayward, so also our convictions are for the good of our migrant neighbors, even if guilty of missing the port of entry. The "guilt" of others is no excuse for not advocating for vulnerable migrants.
On the other hand, if Paul does not mean the gospel leads directly to the religious, social, and political inclusion of ethnic outsiders - then American evangelicals are in a bad way before God. You're not Jewish enough either in blood or in piety to live up to the law of Israel, much less to the kingdom of God. But praise be to God for the messiah, who fulfilled the holy law for all, endured judgment for all, that all may approach the Father through him alone, and not through Israelite religious boundaries, and certainly not through American evangelical mores.