Jesus said that what is outside a man cannot make him impure or unclean. Instead, it is what comes out of a man — out of his heart — that makes him unclean. In the immediate context of Mark 7 he is talking about food and handwashing. We are not made ritually unclean by the things we eat nor by the cleanness of our hands when we eat. What makes us unclean are the things that come out of our hearts. Our actions make us unclean when we sin. So do our words.
But if it is true that nothing outside us can make us ritually unclean, then that truth extends not just to foods but likewise to other people. And so St. Paul says that the divisions among people are effectively shattered by the Cross of Christ. Once, we Gentiles were strangers to the covenant of God, but we who were once far off have now been brought near in Him. We are no longer aliens but citizens with the saints in the kingdom of God (Ephesians 2), and for this reason there is no longer Jew and Greek (racial barriers are destroyed), and there is no longer slave and free (economic barriers are destroyed), and there is no longer male and female (Galatians 3).
What might this mean in the immigration crises the world experiences today? Maybe the best way to think about it is to think about what it would be like if the shoe were on the other foot. What if we were the ones who were emigrating because our native homes were ravaged by poverty and violence and war? Would we not anxiously seek refuge elsewhere? The answer is a simple “Heck YES we would!” We all know this. We in the West know this if we ever stop to think about it. We’d be doing the same thing. On a small scale we already know this, as when people fled New Orleans in the wake of Katrina. So what do we do now when people flee here from other countries? They bring new languages and strange (to us) customs, but they are fleeing from something or other and they are seeking better, safer lives for themselves and their children.
In keeping with Mark 7, these people are not unclean. They are desperate. They are not going to ruin anything here in the USA or in Western Europe or anywhere else. They will not make us unclean or impure. What certainly will do that, though, is our response to their search for refuge and for homes and for help. If we kick them to the curb, it seems pretty clear that we are kicking Jesus to the curb: see Matthew 25. How then will He greet us if we turn them away? It is a fearful thing to consider…