Who Should be Permitted to Enter a Country? (by Steve C. Halbrook)

Scripture assumes that a nation can, or even should, allow some immigrants to dwell in the land. For instance, Leviticus 24:22 holds that one law should apply to the sojourner and native alike—implying that immigrants and natives can live under the same legal-system, and therefore in the same nation. Deuteronomy 24:14, 15 assumes the legitimacy of hiring immigrants as workers—and therefore the legitimacy of immigration itself. In Israel, immigrants were permitted to voluntarily join the religious community, which again assumes the legitimacy of immigration:

If a stranger shall sojourn with you and would keep the Passover to the Lord, let all his males be circumcised. Then he may come near and keep it; he shall be as a native of the land. But no uncircumcised person shall eat of it. (Exodus 12:48)

This also seems to imply that at least in a Christian nation, outwardly converting to Christianity is not to be coerced, but voluntary; at the same time, immigrants cannot outwardly worship false gods or promote false religions (e.g. Exodus 22:20, Deuteronomy 13)—they must keep their unbelief to themselves.

The fact that Scripture allows those from other countries to dwell in the land without a restriction on race precludes the racist idea that a nation should only admit those of the same race of its inhabitants. 

All who are willing to dwell in a country peacefully and according to its righteous laws should be considered for living in the land. Special preference should be given to the helpless ("Religion that is pure and undefiled before God, the Father, is this: to visit orphans and widows in their affliction ...", James 1:27a) and Christians ("So then, as we have opportunity, let us do good to everyone, and especially to those who are of the household of faith", Galatians 6:10). 

Regarding the latter, the wise King Solomon longed for the immigration to his country of foreigners who wanted to worship the one true God (1 Kings 8:41-43). Moreover, nations can be a safe refuge for God's people. Joseph, who ruled Egypt, had his family admitted into the country to save them from famine (Genesis 45, 46). When David fled from Saul, the land of Gath provided a safe refuge (1 Samuel 27:1-4). After the birth of Jesus, Joseph found refuge in Egypt to escape Herod (Matthew 2:13-15). 

When King Sihon of Heshbon refused to allow the Israelites to pass through his land, God judged Heshbon (Deuteronomy 2:24-34). Nations, then, should think twice about refusing to admit God's people:

I will bless those who bless you, and him who dishonors you I will curse. (Genesis 12:3a)  

Truly, I say to you, as you did it to one of the least of these my brothers, you did it to me. (Matthew 25:40b)

Truly, I say to you, as you did not do it to one of the least of these, you did not do it to me. (Matthew 25:45b)

To a large degree, America itself began as a refuge for those who sought the freedom to practice Christianity. 

We must also note that a nation cannot (unless it has a biblical reason) forbid foreign missionaries who preach the true Gospel from entering. The Great Commission—which requires Christians to disciple the nations—is backed by Christ, who has "All authority in heaven and on earth" (Matthew 28:17). Since Christ is the highest authority, then His authority trumps that of nations that oppose the entrance of Christian missionaries.

And in a Christian nation, it is suicidal to allow the entrance of those who refuse to give up practicing and promoting a false religion, or, for that matter, promoting damnable heresy in the name of Christianity (such as denying justification by faith alone). Attacks on the foundations of Christianity are attacks on the foundations of a Christian social order (cf. Deuteronomy 13).

However, as we previously noted, one doesn't necessarily have to embrace Christianity to enter a nation; but if he rejects it, he must not do so openly.

Finally, a nation's hostility towards Christians may be grounds for barring (at least for a period of time) the hostile nation's people from entering another country. One can judge for himself whether the following passage has a degree of application today, or was simply a unique historical circumstance for Israel. Note especially that it says "You shall not seek their peace or their prosperity all your days forever":

No Ammonite or Moabite may enter the assembly of the Lord. Even to the tenth generation, none of them may enter the assembly of the Lord forever, because they did not meet you with bread and with water on the way, when you came out of Egypt, and because they hired against you Balaam the son of Beor from Pethor of Mesopotamia, to curse you. But the Lord your God would not listen to Balaam; instead the Lord your God turned the curse into a blessing for you, because the Lord your God loved you. You shall not seek their peace or their prosperity all your days forever. (Deuteronomy 23:3-6)

Many more considerations could be made about admitting immigrants. One final consideration here is the prospect of banishment: perhaps immigrants can initially be put on probation, so that if their behavior shows that they entered the land under false pretenses (such as claiming to respect the law when they don't, or claiming to be a Christian when their lifestyle shows otherwise), then they would be expelled. 

From Border Meltdown: Biblical Principles to Address our Immigration Crisis by Steve C. Halbrook