Reviewing a book titled The Son of Man written by François Mauriac (a French Roman Catholic who wrote about the problems of good and evil in human nature and in the world), Flannery O’Connor writes:
He proposes in the place of that anguish that Gide called the Catholic’s ‘cramp of salvation’ obsession with personal salvation an anguish transmuted into charity, anguish for another. Thus for Sartre, ‘hell is other people,’ but for the Christian with Mauriac’s anguish others are Christ. We realize that this way of looking at life was so completely left out of Mauriac’s youthful Catholic education that it has had to come to him as a discovery of later life. (The Presence of Grace and Other Book Reviews by Flannery O’Connor)
What caught my attention is that quote about Sartre, that “hell is other people.” The Christian perspective, informed by the reality of Christ and the work of grace, is that “others are Christ.” That is one of the best descriptions of a sacramental worldview that you will find in one sentence.