There's a LOT of anti-immigration sentiment in America. This blog post is not going to discuss politics, but rather, look at what God told His people (the Israelites) through His Word (the Bible) in regards to how to treat foreigners.
We are not to mistreat foreigners. (Exodus 22:21)
We are not to oppress foreigners. (Exodus 22:21 and Exodus 23:9)
We are to treat foreigners like the native-born citizens. (Leviticus 19:34)
We are to love them as we love ourselves. (Leviticus 19:34 and Deut. 10:19)
But what if they are here illegally?
That's for the government to deal with. If someone is here illegally, you still aren't to hire them (it's the law), but loving our neighbor and our treatment of foreigners still apply.
But what if they're taking our jobs?
Trust in God to provide. Be willing to relocate or work with people who are different than you.
But what if they're leaving their countries to come to ours?
You can't control their actions, but you can choose to welcome them (show them Christ's love) or spurn them.
But what if they're sending money back to their countries?
Go to another country and live like the average person. See if you can make it on only their wages.
Over and over again, the Israelites were commanded to care for foreigners, because they knew what it was like to be a stranger in a strange land.
Bottom line? God commands us to be kind to foreigners. Most commands God gives us do not hinge on others' behavior, but that God says to do _____. Period. We will have to answer for our conduct one day before Him, so be kind to foreigners.