JOHN UPDIKE'S new novel, Couples, describes a modern purgatory, a world from which God has withdrawn, a community without grace or light or love. The book, the story of various adulterous affairs among a group of affluent suburban couples, bears an ironic quotation from Paul Tillich that outlines the novel's thesis. The quotation tells us that when the average citizen feels that "the decisions relating to the life of the society to which he belongs are a matter of fate on which he has no influence," then a mood is created that "is favorable to the resurgence of religion, but unfavorable to the preservation of a living democracy."

The affairs of the novel take place against a backdrop of news headlines, introduced peripherally by the author. Like "matters of fate" they impinge hardly at all upon the consciousness of the adulterers. Kennedy's assassination, for example, does not deter a drunken party, for after all, as the host Freddy Thorne says, "I've bought all the booze."

The rents in the fabric of national life do not lead to a resurgence of the Christian religion. They are in fact the signs of God's withdrawal from our republic. In the end, as a last judgment of God, or of the author, The Tarbox Congregational Church is struck by lightning. Only the gold weathercock on the spire, the symbol of God's watchful but now indifferent eye, is spared in the ensuing fire. Eventually even this emblem is hauled down from its pinnacle. Placed in the hands of the Church's absurd minister it is found to measure only "five feet from beak to tail feathers; the copper penny of his eye was tiny."

The resurgent religion is not Christianity then, but a perverse humanism. The affluent young couples of Tarbox, Mass. find the comforts that religion used to provide--the alleviation of one's fear of death, the sense of community, the transfiguration of the world--not in the Church, but in their relations with each other.

Their word games, their parties, are the new rituals and ceremonies. Their sacrament is adultery. The binding force of the new religion is not love but sexuality. The community is united not by faith or the Host, but by the orifices of the body. Together the couples form a congregation, "a circle of heads to keep out the night."

They have merged their identities in the mystic experience of adultery, losing, like saintly communities, their individuality. The Applebys and the Smiths become "the Applesmiths." The Saltzes and the Constantines merge to form "the Saltines."

FOR MUCH of the novel it is impossible to remember who is married to whom. In adultery the tenuous meaning we create by marriage is destroyed, and one human is the same as any other. Eros is no respector of persons. Sexuality is a force as indifferent as electricity to the copper wire of our bodies. Women are, as Piet Hanema, the main character says, "vessels to be filled."

Love in Tarbox is not a free and unmerited human grace, but a mask of fear. Love-making is for Piet a way of momentarily escaping his haunting fear of death, a way of forgetting the reality of loss, the eventual extinction of consciousness.

One love affair is allowed momentarily to flourish in the marshes of Tarbox, and its individuality is contrasted to the interchangeable lust of the others. This is Piet's love for Foxy Whitman, a lady for whom the author too seems to have had some love, for he has made her a luminous and appealing character. But this affair glows only briefly. And though Piet and Foxy do marry, they do so long after their love has died.

In the end I am left with the impression that most human feelings are absent in Tarbox. Though Piet has a momentary infusion of paternal love, it seems like no more than a nod to that feeling on the part of the author, a reflex in his own character. Piet eventually leaves his two young children without any deeply anguishing regrets. Children in Tarbox are mainly encumbrances to their parents. They are bundled up and transported, even when sick and feverish, so that the couples may continue their adulterous visits. It is the children who finally give an air of pathos to the network of affairs that makes up the novel.

But the actual life of the book seems to me not in its thesis about the withdrawal of God, but in its repulsive vision of the absence of love and grace from human relations. Unfortunately the thesis seems to crush the book's main character, to drain the life from him. Piet is, supposedly, the scapegoat of the couples. And it is the group's judgment that Piet was used by Foxy in order to discard her cold-fish husband. But to see him as a scapegoat is to accept him as will less--and so the author seems to have viewed him.

Piet is unable to refuse an encounter. At the end of the book he has been drained of all sense of choice, of free action. His will has been sacrificed to the author's formulation. It is perhaps this sense of authorial intrusion that is the novel's main flaw, that accounts for its lack of expansiveness, its lack of extended meanings, its lack of resonance.

It may be my own wish that the world not be as Updike sees it--cold, without essential human feelings or grandeur--that causes me to seek a refuge in these artistic strictures. But Couples does seem a novel in which the author's volition, his thesis, have been allowed to substitute for the free play of the imagination, for a full measure of humanity for his characters.

But what has been denied the human heart in Couples has been lavished freely on the appearances of things. The book contains the most subtle renderings of the face of nature, the bleak marshes near Foxy's house, the constantly changing face of the ocean:

At times the sea was steely purple, stained; at others, under a close warm rain sky, the no-color of dirty wash; choppy rows hurried in from the horizon to be delivered and disposed of in the lick and slide at the shore. Piet stopped to pick up angel wings, razor clam shells, sand dollars with their infallibly etched star and their considerate airhole for an inhabiting creature Piet could not picture.

EVERY CRITIC has a position on Updike's style. It is "stale garlic" to Norman Mailer, "angel tongued" to most newspaper reviewers, "sometimes excessive" to Time magazine. Perhaps Updike's prose is overwrought and given to excess, to showing off. But it is in their excesses, as Updike once said of J. D. Salinger, that "artists become adventurers for us all." And it is, at least upon most occasions, an excess of love.

In rendering the sensations of love-making Updike can become silly, almost ridiculous. But often he does describe these sensations in a supple ecstatic prose, with an extraordinary sensitivity to the nuances of physical movement. His perceptions then are concrete and lovely and extend our own sense of the way love can be.

Updike's prose is, like Proust's, imbued with a sense of loss, with a profound perception of the evanescence of things, analogous to Piet's fear of death. It is this that drives Updike to greater and greater feats of observation. Everything, all the world's shapes and colors, must be preserved in words, as in amber, against its eventual decay and disappearance.

The characteristic tone of Updike's prose is elegiac. He is, by his attention to it, paying homage to the world, preserving it, transfiguring it, declaring it all worth saving. One can quote at random from his novel, for every page has gems of observation, rhythmic and charming passages of prose. Only the transcribed stream-of-consciousness of Piet is ever dull or banal.

Updike's charm is often coquettish, flirtatious, a just sufficient enticement to continue reading. But it is also often a lavish measure of light, a stunning gift. It reminds us that prose writing can be an ecstatic art. It opens our eyes to the world. It returns the world to us, after we have read him, more our own than it was before.