Limber, funny and as in touch with the pleasures of the flesh as it is with the pleasures of the game, "Bull Durham," the new baseball movie starring Kevin Costner and Susan Sarandon, eases up on you, lazy as a cloud, and carries you off in a mood of exquisite delight. To borrow W.P. Kinsella's phrase, it has the thrill of the grass.

The movie begins on a slow, stirring, soulful note, and that's the way it's pitched -- as a kind of rousing, gospel testimony. And the witnesses here are like born-again zealots, spreading the holy word. This is a movie about true believers, and if beforehand you're not a member of their church, by the end you'll be raring to join up.

The tent-revival soulfulness of the film's opening moments is sustained throughout its entire length. Combine this with loopy comedy and you've got a great mix. The people that writer-director Ron Shelton has created are the richest, looniest, most cherishable characters to appear in a movie in ages. They're built out of real sinew and bone, and they look substantial up there on the screen, as if they've lived and learned, and will go on living and learning after the movie is over.

The heart and soul of the film is a part-time community college English teacher and full-time hardball devotee named Annie (Susan Sarandon). The movie's opening monologue is Annie's, and not only does it function as a statement of her personal principles, it also defines the film's areas of exploration -- baseball, sex and the ontological mysteries of the universe. Seen unsympathetically, Annie might seem to be the sort of woman who hangs around ballparks looking to make conquests -- a mere baseball groupie. But for Annie, baseball is a governing metaphor, and it's through her eyes and her pagan devotion to the game that we see the film's events.

Every year Annie selects the hottest-looking prospect and takes him as her lover for that season. Her pick for the current year is a fireballin' flake named Ebby Calvin LaLoosh (Tim Robbins), a still-wet-behind-the-ears bonus baby with "a million-dollar arm and a five-cent head" who's been sent to the hometown Durham Bulls for a little seasoning. Actually, more than a little seasoning is needed because Ebby Calvin's heaters are as likely to hit the team mascot, or go sailing into the broadcast booth, as they are to find the strike zone. And to help mature this green talent, the team organization brings in Crash Davis (Kevin Costner), a catcher near the end of his career, to work the kid into shape for "the show," the movie's slang for the majors.

As Annie sees it, this is pretty much her role, too, though her education focuses less on the youngster's baseball skills than on such aspects of "life wisdom" as bondage, Walt "Limpid Jets of Love" Whitman and the breathing habits of the South American lava lizard. And so while Crash teaches him everything from how to throw a breaking ball to how to give an interview, Annie has him wear a garter belt under his uniform to reorient his head and get him pitching out of the proper hemisphere of his brain.

Shelton keeps shifting the relationships among these three characters, giving first one and then another the upper hand. And his script takes us deep inside their heads. This is Shelton's first film as a director (he wrote "Under Fire" and "The Best of Times"), and at times his staging of scenes is awkward, but he's a fully developed scenarist with a wonderfully organic sense of comedy. And the strength of the writing, plus his assurance with his characters, carries us over any rough spots.

He's assisted in this by nearly flawless performances from his actors. As Annie, Sarandon functions as both Boswell and muse for the Bulls. From her seat in the stands, she sends word when they're pulling their hips out too soon or not bending their backs. In her scenes with the young Ebby Calvin (whom she nicknames "Nuke"), she's a wise mother and willing playmate combined. And the aura of womanly experience she projects seems to give the film a larger context. She makes it more than just a film about baseball.

As Nuke, Robbins, who starred in "Five Corners," is a delicious oddball with sneaky eyes and a disarming, boyish smile. Robbins, who's tall and physically quite imposing, gives remarkably subtle and detailed line readings. For such a big guy, he's got a sweetly gentle style. A different approach might have turned Nuke into a lug, but instead Robbins makes him a likable innocent.

Annie's scenes with Nuke are like initiation rituals. But her scenes with Crash have a different chemistry; they meet more as equals, and so their encounters are more resonant. The movie seems to take its pace from the rhythms of the game, and from its North Carolina setting. And Costner's performance, too, seems to be in sync with both. For once Costner has a role that he can sink into, that fits his skills, and he shows enormous authority and charm. Physically, it's a marvelous incarnation: He swings well (from both sides of the plate) and even has a good home run trot. He's totally in his jock character's body, and with this one performance, he emerges as a true star presence.

What "Bull Durham" plunges us deep into is the sentimental notion, dearly held by die-hard fans, that baseball is more than a mere game; that it is profound, metaphysical, paradigmatic. This approach usually results in baseball movies that are too reverential, like "Pride of the Yankees," or in bloated allegories, like "The Natural." But "Bull Durham" is neither turgid nor worshipful. The film has the virtues that Annie says a good hitter must have -- it's concentrated and relaxed.

Movies that take an inflated view of baseball usually have no feel for the everyday details of the game, for what it's like to be in the locker room or the dugout and smell the dirt and the liniment and the tobacco juice. "Bull Durham" sees the game in its larger dimensions without losing those details.

What it has is flavor, reality, a sense that the game is played by actual people, boys mostly, and not heroes. The people associated with "Bull Durham" know the game -- Shelton spent five years in the minors with the Orioles organization -- and the firsthand experience shows in their easy command of the ballplayer's vernacular, in their feel for what goes through a batter's head when he digs in at the plate and in their knowledge of the secret ceremonies that take place on the mound.