“Christian libertarianism” has come to have a following among a certain segment of American Christianity.  As applied to government border and immigration policy, here is how Christian libertarian proponent Bojidar Marinov describes it:

"The only true way to counter what this administration is doing is to demand the good old Christian conservative solution: Repeal all immigration laws and deprive the Federal government of the power to control the movement of individuals who haven't committed any real crime. As long as conservatives stupidly demand enforcing the same socialist laws and "tightening the borders," they are playing in the hands of this administration. Being useful idiots for Obama can't be an effective opposition to what Obama is doing....Biblically, borders delineate the extent of legal enforcement of laws by specific governments, not the extent to which a private individual who has committed no crime can travel or settle. Therefore, Biblically, borders are established to LIMIT GOVERNMENTS and to ensure the political decentralization of the land. In their foolishness, modern American churchianity and conservatism have the opposite vision for borders: more power to the government, more political centralization, and less freedom for individuals. This is nothing less than socialism and statism...."

For purposes of this brief article I will set aside addressing Mr. Marinov’s historically inaccurate suggestion that his expressed view represents the “old Christian conservative solution” in America (and its contrary “modern American churchianity”), but instead focus on his point theologically. Let’s first be clear that “Christian libertarianism” is contrary to the Westminster Standards, and far more importantly the Bible.  The Bible is clear that the civil magistrate has a duty to enforce the moral law of God summarized in the Ten Commandments, which is very different from what any form of libertarianism proposes. 

The Westminster Standards speak to the issue of border and immigration policy in its statements relating to “lawful war”:

WCF Chapter 23, Section II.–It is lawful for Christians to accept and execute the office of a magistrate when called thereunto; in the managing whereof, as they ought especially to maintain piety, justice, and peace, according to the wholesome laws of each commonwealth, so, for that end, they may lawfully, now under the New Testament, wage war upon just and necessary occasions.

WLC Q. 136. What are the sins forbidden in the sixth commandment?  A. The sins forbidden in the sixth commandment are, all taking away the life of ourselves,[746] or of others,[747] except in case of public justice,[748] lawful war,[749] or necessary defence;[750] the neglecting or withdrawing the lawful and necessary means of preservation of life…  [749] Jeremiah 48:10. Cursed be he that doeth the work of the LORD deceitfully, and cursed be he that keepeth back his sword from blood. Deuteronomy 20:1. When thou goest out to battle against thine enemies, and seest horses, and chariots, and a people more than thou, be not afraid of them: for the LORD thy God is with thee, which brought thee up out of the land of Egypt…

Here is how Robert Shaw describes it in his Exposition of the Westminster Confession of Faith:

“Christian magistrates may lawfully, now under the New Testament, wage war upon just and necessary occasions. War must be regarded as a great evil, but in the present state of the world it is sometimes necessary; and if a nation were to adopt and act upon the principle that war is absolutely unlawful, it would soon become a prey to its ambitious neighbours. Under the Old Testament, wars were undertaken by the express command and with the approbation of God; but he could never command and approve of what is morally wrong. In the New Testament, too, there are various circumstances stated which countenance the lawfulness of magistrates waging war, and of Christians bearing arms. When the soldiers inquired of John what they should do, he said unto them, "Do violence to no man, neither accuse any falsely;" but he did not command them to relinquish their profession, as unlawful; on the contrary, the precept which he added, "Be content with your wages," supposed them to continue in their situation.–Luke iii. 14. The first Gentile convert who was received into the Christian Church was a centurion; but Peter, when he baptised him, did not require him to give up his situation in the Roman army.–Acts x. To determine the several cases in which war may be justifiable would be out of place here; it may, however, be generally stated, that aggressive wars, or such as are undertaken to gratify views of ambition or worldly aggrandisement, cannot be justified; but that defensive wars, or those which, as to the first occasion of them, are defensive, though in their progress they must often be offensive, are lawful.”

So the Westminster Standards clearly uphold the Biblical principle of lawful war.  How does that relate to border and immigration policy?  Here is one way to think about it.  Let’s say Americans believed the “Christian libertarian” view of border policy.  Then all that China would have to do to conquer America is simply encourage a fair number of its people to move into America, vote for candidates who would want to merge America into China, and then have their elected candidates effect such merger.  Nations could hence be taken over and conquered without a shot being fired.  The lawful war position upheld by the Westminster Standards, in contrast, presupposes that nations will defend their borders (and have the right to do so) from such free movement of people, such that the only way for one nation to conquer another is by force of arms.  The lawful war position of the Westminster Standards teaches that the civil magistrate of a given nation has the right and responsibility to use arms to prevent such conquest of its nation.  It presupposes each nation has property rights even as individuals have property rights, and one duty of the civil magistrates is to protect those property rights, by use of arms if necessary.  By implication, a civil magistrate has the right to use arms to control the flow of people across its borders so as to maintain and protect its national integrity for its own people.  According to the Bible, and implied in the Westminster Standards, it is a judgment on a people and nation for them to lose the ability to control their borders (what scripture calls “hedges”) in this way: "Why hast thou [then] broken down her hedges, so that all they which pass by the way do pluck her?" (Psalm 80:12) 

If the people of a nation are losing the will to protect their borders, adopting “Christian libertarian” views, that itself is indicative of the judgment of God upon such people.  They are losing wisdom even to defend themselves and their nation.