(this is taken from a lecture given at the Bucer Institute on Flannery O’Connor; thanks to Doug Jones, Peter Leithart, and others who’ve helped me to appreciate her even more than I did already)
One of the things we see throughout Flannery O’Connor’s writings is the truth that God works in and through the physical and material. God works through fire and water; bulls and peacocks; cats and grandmothers; and, of course, ultimately through His Word read and proclaimed, and in the waters of baptism, and by the bread and wine of the table. The prominence of this reality in her writings was intentional not accidental. She was attacking the gnosticism of the modern Church; the denial that the material and physical can be means by which we commune with the Lord.
For too many of us, bread is simply bread, wine is only wine, water is merely water and nothing more. Bread and wine can never be the means by which we commune with Christ and feast upon His body and blood. Water can never be the means by which the Spirit brings us into communion with the Trinity. The Church must only be an assembly of people who profess the same theology, it can’t be “the body of Christ.” Not really.
O’Connor had no patience with this non-sacramental view of life. Once when visiting New York, Flannery was invited to a dinner party hosted by the poet Robert Lowell. Among the guests was the famous novelist Mary McCarthy. McCarthy was a lapsed Roman Catholic and held the Church (and the faith itself) in disdain. The conversation turned to views of the Eucharist and McCarthy stated that when she was a girl and received the host, she thought it was the Holy Ghost but now, she said, she thought of it as “a symbol and a pretty good one.” Flannery had said little all evening but this comment provoked her. She replied in a very shaky voice, “Well, if it’s a symbol, to hell with it.”
In writing about this incident later, she noted, “this was all the defense I was capable of but I realize now that this is all I will ever be able to say about it, outside of a story, except that [the Eucharist] is the center of existence for me; all the rest of life is expendable.” (A Habit of Being, 123).
Biblically, “signs” are not merely pictures — they are acts which accomplish things (they are the signs and wonders God does in the earth, think of the “signs” God showed to Egypt prior to the Exodus). The sacraments are not mere signs of things absent or invisible, they are acts of God, actions of grace.
In O’Connor’s writings the sacraments (and exaggerated pictures of the sacraments) are central. But she went even further. To Flannery, the entire creation was sacramental. We live in a world in which particular things, while remaining what they are, confront us with the reality of God. For this reason she denounced Manicheanism — the view that the creation, the material, was evil in itself. The way of purity and true spirituality, according to the Manichaes, was to separate oneself from physical things and seek direct intercourse with the Divine. Biblical religion, by contrast, teaches that creation is the medium by which God comes to us.
It is this reality which guided O’Connor’s work. She argued that Christian writers must not attempt to bypass creation (by writing about ideas, principles, or other abstractions) but rather must expect to find the “presence of grace as it appears in nature.” She said, “Most people who think they want to write stories are not willing to start there. They want to write about problems, not people; or about abstract issues, not concrete situations.” It was O’Connor’s ability to avoid this trap that made her writing so startling and, ultimately, so distinct from other Christian writing of the last century.
Christian authors would be greatly helped to follow Flannery’s insight . . . and so would Christian theologians.

What a wonderful post! Thank you.
[...] For too many of us, bread is simply bread, wine is only wine, water is merely water and nothing more. Bread and wine can never be the means by which we commune with Christ and feast upon His body and blood. Water can never be the means by which the Spirit brings us into communion with the Trinity. The Church must only be an assembly of people who profess the same theology, it can’t be “the body of Christ.” Not really. “ [...]