LION COUNTRY, by Frederick Buechner. Antheum, $5.95.

THE NOVEL is the major literary form of modern Western civilization, although its exponents have almost managed to kill it: A day never goes by at any newspaper without the arrival of review copies of at least five or six new novels, each worse than the one before, each proclaimed by its publisher as the literary epic of the century, each accompanied by a favorable blurb from Publisher's Weekly. (I don't think PW has ever not liked a book.)

A lot of people have put a lot of work into killing the novel-Leon Uris and Fletcher Knebel and Irving Wallace and all those names which make you want to be sick. Tons of paper have been wasted on bringing their effluents before the public, and tons of celluloid on converting them to major motion pictures. Although each of these authors has sold millions of books, none of them will be remembered a decade from now, because they all share one common outstanding quality-forgetability.

I don't know why, exactly, the state of the novel is so bad. I suppose that the growth of journalism in the past few centuries has had a lot to do with it-people are used to reading prose that is straightforward, factual, and dull, which tells a story in the fewest possible words and doesn't bore them with details. The result, of course, has been that English prose style has gone straight to Hell. The Erich Segals of this world are cleaning up on junk that shouldn't get them a passing grade in English C.

ONE WRITER who has never indulged in this sort of bleary prose style is Frederick Buechner. In the twenty or so years during which he has been publishing novels, he has never turned one out in the sort of journalese which is so popular nowadays. If anything, his problem has been just the opposite. Rather than being simple and ludicrous, his plots have been intricate and Byzantine, his style deep and tricky. For just that reason, he hasn't had a major success since the publication of Long Day's Dying in 1950. In the interim he has tried, again and again, to produce a first rate novel, and never quite succeeded. For fun, he has also taught English, and, last year, gave the Noble Lectures at the Harvard Divinity School.

Perseverance is an admirable quality, and it often gets results. It finally has for Buechner. Lion Country , his latest novel, is the most entertaining piece of fiction published in this country since Updike's Bech: A Book . Buechner has given up his sententious themes, and toned down his murky style a bit, to produce a highly amusing novel about a bunch of remarkably strange people.

Buechner's characters do not easily lend themselves to humor. The narrator is a bachelor approaching middle age, who lives with his cat on the Upper East Side, and goes to the hospital every day, to visit his twin sister, who is dying of a bone disease, and has just been divorced by her husband. The narrator's subject is the middle-aged founder of a Southern fundamentalist religion, which ordains anybody to the ministry by request (and the payment of a love offering), a former Bible salesman who did five years in jail for exhibitionism. The other characters are all refugees from every depressing Harold Pinter play you've ever seen-a virtual corps de ballet of nymphomaniacs, alcoholics, homosexuals, and a seventy-five year old Indian millionaire worried about his potency.

It is hard to understand just how Buechner makes this all work, but, somehow, he does. The novel is extremely entertaining, very funny, but not frivolous. The plot is not overwhelmingly brilliant, merely an opportunity for Buechner to exercise his talent at describing and delineating characters. Throughout the book, he uses that talent to best effect, never descending to cheapness to make a point. His description of his protagonist's first act of exhibitionism is the most lyrical periphrasis of a grisly subject I have ever seen, a masterpiece of style and taste.

If there is a major fault in the book, it is the ending, which limps. But Buechner recognizes this, for he begins his last chapter with a quasi-confession of the fact. But this does not make the book any less worthwhile. Read it for fun, read it as a good example of prose style, or read it for his description of the electric cross above the Church of Holy Love, but by all means, read it.