WRITING THIS REVIEW is a painful obligation.

Larry Woiwode is a writer whose work I admire enormously, even passionately. His first novel, What I'm Going to Do, I Think, published in 1969, is a work of remarkable maturity and depth; his second, Beyond the Bedroom Wall, published in 1975, is by any standard a major American novel, one that envelops the reader in its world with breathtaking immediacy. By contrast with these two, Poppa John is a terrible disappointment, its luminous prose notwithstanding.

The novel's seriousness and earnestness are transparent and, considering its ultimate failure, almost heartbreaking. What Woiwode is trying to do here is bold and, in a cynical age, unfashionable: to convey the emotional struggles and doubts attendant to a discovery of religious faith. It is a novel the climactic sentence of which is: "I believe in God." It is almost childlike-- deliberately so, I believe--in its statement of that belief; Woiwode wants to make the reader feel the innocence and awe with which a man at last meets his maker. But he simply does not pull it off; the crucial moment that he intends to be an epiphany fails to rise above the level of soap opera.

Which is an unfortunate irony, since the Poppa John of the title is the name of a soap-opera character played by the novel's protagonist, Ned Daley. Now in his late sixties, Daley has just been removed from the series: "For a dozen years he'd been Poppa John to millions of viewers, of every age and sort, and more of them had watched his death this fall, it was estimated, than the funeral of young President Kennedy, several seasons ago." Poppa John was the genial, avuncular conscience of the show, a kindly old fellow who spouted appropriate quotations from the Bible for each and every occasion; the device had been suggested by Daley as the role was taking shape, in affectionate recollection of his own grandfather, a minister.

For Daley the "death" of Poppa John is a traumatic event. On the one hand it offers the prospect of rebirth, the chance to turn from the soaps back to the classical theater in which he was originally trained. But on the other it forces him to confront the realities of life that Poppa John shielded him from: " . . . once a character of such continual standing, whose gaps and limits are known, is established as benign, he's controllable; he won't slip back into the unpredictable pitfalls that can seize your entire attention in the blind and tortuous negotiations you undergo in a real self."

Denied the mantle of Poppa John, Daley is forced gradually to rediscover himself, his past and his flaws. It is not a pleasant process. The season is Christmas; as he shops with his devoted wife, Celia, he finds the music of the season in stark contrast with his mood. Above all he is haunted by the memory of his father's murder when Daley was a boy; a half-century later he still wonders whether he might have been able to prevent it, and his dreams are still troubled by his doubts.

Fatherhood, as the novel's title suggests, is a central theme. Daley remembers his father and his grandfather, and he casts his eye uncertainly to his Father above. He once raised the subject with an interviewer:

"Poppa John mentioned what was particularly significant to him about the role, from the day he'd tried out for it, which he'd been saving for this interview; how he'd felt at home in the name of Poppa John the moment he'd heard it, because of his grandfather's interpretation of the verse in Matthew: And call no man your father upon the earth: for one is your Father, which is in heaven--that it was meant literally. And so he'd grown up with names like Pop, Poppa, Grampop, and the like. . . ."

What Daley comes to understand as he struggles with these ghosts is that he used his past, and his grandfather's faith, as mere props in the playing of his role. He studied the Bible carefully, and was moved and instructed by it, but his real purpose was to obtain lines to use on the show, quotations that would be precisely apt to the imaginary situations in which he had been placed. He comes to understand, too, that television can be deception, that what it presents to those who watch is sometimes not reality but a lie.

This point is brought home to him most forcefully when he finds himself messily drunk and in the company of a young woman who had idolized the Poppa John she knew on television. "I've always wanted to meet you," she tells him, "to find out what goes on in your head, and what you're actually up to, and if this is what you're up to, it sucks. . . . You're drunk. You talk too much. If men like you get like this, what's the use. Who is there to look up to?" He knows there is "self- righteousness" in her words, but there is also truth. Jarred by the woman's disillusionment and contempt-- and love--he comes in the end to his moment of revelation, to his discovery of genuine faith.

He does, but the reader does not. Poppa John preaches and teaches, but it does not move--nor does it, as Woiwode clearly wishes it to, persuade. Unlike his previous novels, which were grounded in memory, grief, love and longing, Poppa John is grounded in a rather smug religiosity; it's an evangelical novel in which the message is of greater importance than the medium. Themes are hurled at the reader in abundance; yet there is little in the way of character or incident or structure to give weight to them, to make the reader care.

The faith that permeates the novel is attractive, but the programmatic manner in which it is explicated is not: "Then a new and separate force approached in a rush, as down the open empty hall where his pop had disappeared so many nights, blowing open all the doors of all his senses to the frozen note where time revolved and wheeled: the presence of the man of sorrows, acquainted with his grief, Christ as Lord." Yes, those are lovely words, but they are melodramatic--as is the entire scene in which Poppa John at last confronts his mortality and his faith.

It is not given to many novelists to write interestingly or originally about ideas; people and places and emotions are, by and large, the provinces most comfortably occupied by writers of fiction. In his first two novels Larry Woiwode occupied this latter territory, and with brilliant results. In Poppa John he attempts the former, and he fails. He tries to say too much and ends up saying very little.

So let's hope that Poppa John has gotten the preaching out of Woiwode's system, and that he will now feel free to return to the work for which his maker clearly intended him: the telling of mysterious, wrenching, shimmering stories.