The teaching of this saying is very simple, yet it is one that deserves continual repetition. There is a similar saying, Romanian I think, that says, “Your neighbor is your salvation.” The point being that every relationship we have holds ultimate significance, because every human being is created in the image of God.
Jesus says as much in one prophecy:
“When the Son of Man comes in His glory, and all the holy angels with Him, then He will sit on the throne of His glory. All the nations will be gathered before Him, and He will separate them one from another, as a shepherd divides his sheep from the goats. And He will set the sheep on His right hand, but the goats on the left. Then the King will say to those on His right hand, ‘Come, you blessed of My Father, inherit the kingdom prepared for you from the foundation of the world: for I was hungry and you gave Me food; I was thirsty and you gave Me drink; I was a stranger and you took Me in; I was naked and you clothed Me; I was sick and you visited Me; I was in prison and you came to Me.’
“Then the righteous will answer Him, saying, ‘Lord, when did we see You hungry and feed You, or thirsty and give You drink? When did we see You a stranger and take You in, or naked and clothe You? Or when did we see You sick, or in prison, and come to You?’ And the King will answer and say to them, ‘Assuredly, I say to you, inasmuch as you did it to one of the least of these My brethren, you did it to Me.’” (Matthew 25:31-40)
“Son of Man” is a common way that Jesus referred to himself. It is a Semitic idiom meaning “human” (the son of a human is human), but came to have an additional messianic, perhaps even divine, connotation in Hebrew prophecy. Thus, he is affirming his humanity, while also claiming to be the Christ who was prophesied to come, even possibly hinting at his divinity (though the phrase “Son of God” and others pretty much cover that).
The point being that this prophecy is about Christ’s return to judge the world. Please, if possible, put out of your mind any bumper-sticker characterizations of this idea, because I can say with confidence that the ones I’ve seen cannot possibly mean what Jesus means here. Let us put aside speculation and focus on what is clear: Jesus is teaching the standard by which he shall “come again in glory to judge the living and the dead,” to quote the Nicene Creed. The standard is simple, just as St. Antony puts it so well: “From our neighbour are life and death. If we do good to our neighbour, we do good to God: if we cause our neighbour to stumble, we sin against Christ.”
Now, it could be that Jesus simply attributes the good or evil we do to others to himself by fiat, but there is actually a deeper foundation. According to the Scriptures, all human beings are made in the image of God. Think, for example, of an ancient king. Kings often had a signet ring by which they would seal a letter, pressing the image on the ring into wax, denoting that the message comes by their authority, and the messenger would then speak on their behalf, saying, “Thus says the king,” and so on. Human beings, in some way, are like royal letters, impressed with the image of the King.
There is much theology that can be and has been gleaned from this, but I would like to dwell on the image itself. Just as the messenger spoke on behalf of the king, so also if someone scorned the message, their action would be seen as treason, as if they had defied the king to his face. In the same way, ancient people honored images of royalty for the sake of the royal persons depicted. The assumption being, to borrow a principle from St. Basil, “the honour paid to the image passes on to the prototype.”
Now, if we apply this principle to the idea that, in some way, all human beings bear the impress of the image of God, we can see a little more clearly why “[i]f we do good to our neighbour, we do good to God.” It is a matter of what we are as human beings. It cannot be otherwise. The honor that we pay to others and the love that we show them—especially the needy and the outcast (the hungry, the thirsty, the foreigner, the naked, the sick, the imprisoned)—passes on to God, in whose image they are created. If we are content to live in comfort while others suffer, and we do nothing to alleviate that suffering in those who are near to us (our neighbors), we not only dishonor them, we dishonor God.
What does this mean in practice? Of course, there is the obvious: “your neighbor is your salvation.” There is good reason why St. Paul says that “love is the fulfillment of the law” (Romans 13:10). However, who doesn’t already know that they should love other people? Even knowing that what we do, we do not only to them, but to Christ, does not always prevent us from failing to love our neighbors as we ought. What we need is to cultivate a daily habit that continually reorients us. One way to do that is to practice the Jesus prayer. By constant meditation on the name of Jesus, we come to see Jesus in everyone we meet—like Mother Teresa, for example. Another way, one with a longstanding tradition among Christians, is through iconography.
Christians have been making and venerating images (or icons) of Christ and the saints since the beginning. I realize that for some today, any sort of religious imagery automatically qualifies as idolatry, but that was not the case for most early Christians (there were some dissenters, but the practice was widespread). Knowing what we do about the images of royalty, however, lets us see what this meant to them. Just as it is not idolatrous to honor the image of a king, but in fact, appropriate given the innate connection between the image and its prototype, so also the love or honor given to images of Christ and the saints “passes on to the prototype.” In doing so, Christians who keep this practice today not only honor the persons depicted, but also continually remind themselves about this innate connection between an image and its prototype. It is yet another habit that can be cultivated to remind us of the great worth of every human being we meet, through whom Christ our God is present to us, hungry and in need of food, thirsty and in need of something to drink, a stranger and in need of hospitality, naked and in need of clothing, sick and in need of a visitor, in prison and longing for some contact with the outside world. And, according to Christ himself, it is whether or not we are willing to venerate these icons, the image of God in the persons we meet, that we will one day be judged.