But a nation is a territory (i.e. a property) that houses a particular people _and their guests_. I don't think it's very Christian to toss your guests out onto the street, if they are generally well-behaved.
But I also think you should control who you allow in as a guest, and you should punish all uninvited guests. I don't think automatic deportation is the appropriate punishment for most uninvited guests. They aren't usually a threat to the nation, so banishment is a punishment unfitting the crime. They should have to plead guilty for trespassing, pay a hefty fine, and apply for a formal invitation, or something, with the nation withholding the right to deny it and deport.
Children (those under 18 or still attending secondary school) and pregnant women should not be deported, even if they misbehave, as they are protected classes.
I think we need more nuance in the whole discussion.