Christ has become our neighbor; or rather, our neighbor is Christ who presents himself to us in this or that form. He presents himself to us, suffering in those who are sick, destitute in those in want, a prisoner in those who are captives, sad in those who mourn. But it is faith that shows him to us thus in his members. And if we do not see him in them, it is because our faith is weak, our love imperfect. That is why St. John says that if we do not love our neighbor whom we see, how can we love God whom we do not see? If we do not love God under the visible form in which he presents himself to us, that is to say in our neighbor, how can we say that we love him in himself, in his divinity?
Blessed Columba Marmion, OSB
Christ the Life of the Soul