HANDLING SIN. By Michael Malone. Little, Brown. 544 pp. $17.95.

HANDLING SIN is a great big endearing picaresque novel. Its reluctant hero, a cautious middle-aged life insurance agent named Raleigh Hayes, sets out on his quest from the little Piedmont town of Thermopylae, North Carolina, accompanied by his bumbling fat friend Mingo Sheffield. Like their literary kinfolk Don Quixote, Sancho Panza and Tom Jones, Raleigh and Mingo leave many a complication behind them, but unlike their predecessors they drive off in a Pinto whose license plate reads "KISSY PU," and Raleigh is (to my knowledge) the first literary picaro ever to receive his marching orders from a tape cassette.

That tape was made by Raleigh's father, Earley Hayes, an antic septuagenarian who cheerfully disappeared from the hospital where he was supposed to be tending his heart condition. Earley bought himself a yellow Cadillac convertible, took $30,000 out of the bank, and kited off with someone described by witnesses as a "teenage colored girl" -- all perfectly in character for Raleigh's irrepressible father. As for the taped message he left behind, it sends Raleigh on a scavenger hunt all over the South as he searches for the people and objects specified by his wacky mentor.

For Earley -- defrocked Episcopal minister, trumpet player, exuberant appreciator of life -- has it in mind to shake Raleigh out of his prudent stodginess. The taped message ends: "I want you to enjoy yourself for once, Specs. I want you to think of this as a holy adventure, by God." In the course of a few hundred pages and dozens of escapades, even Raleigh begins to understand why his father used to call him a worry-wart and "uptight," just "shriveling with virtue." With affectionate relish, Handling Sin traces Raleigh's re-education, from dutiful prig to generous human being.

It's just about impossible to summarize the plot, which sprouts and ramifies like the Hayes family tree. The Hayeses have some of the random energy of You Can't Take it With You and the craggy quirks of a George Price cartoon, to wit Raleigh's formidable old aunt Vicky Anna, a retired missionary, who draws on a large supply of exotic anecdotes to put her home town in perspective. When invited to marvel at a big crowd, Vicky Anna snorts, "You don't know what a big crowd is unless you've sailed steerage from Rangoon to Singapore with a rooster on your head and a leper lying across your legs."

Raleigh's black sheep half-brother, Gates Hayes, accounts for a good deal of the action. Gates is a handsome, engaging swashbuckler whose quixotic sense of humor and perennial cash flow problem generate many entanglements, not all of them on the right side of the law. Gates' former prison cellmate, a tiny wizened crook named Simon "Weeper" Berg, and Toutant Kingstree, a jazz saxophonist, are gradually added to the party, along with a young pregnant hitchhiker who goes into labor while Gates and Raleigh are rescuing a troupe of dancers from the clutches of the Ku Klux Klan.

Not only that, but there are such episodes as the Kidnapping by Hell's Angels, the Great Adventure of the Bass Fiddle Case, the Famous Barbeque at Wild Walks, the Duel with Cupid Parisi Calhoun for the Alleged Inaugural Necklace of Mrs. Jefferson Davis, and the Glorious Battle of Stone Mountain. The last is a knockdown dragout Keystone Kops production number in which our hero finds himself clinging to the outside of a cable car as it rises dizzily to the top of a southern Mount Rushmore. Very few stops go unpulled, so that the list of picaresque features includes amazing coincidences, buried treasure, mistaken identity, long-lost relatives, supposed murders, and perilously narrow escapes The events may strain credulity with their slapstick broadness, but the timing is wonderfully precise.

IN HIS PROLOGUE, Michael Malone acknowledges his debt to the "friendship, nudges, winks, and wise teaching" of Cervantes, Fielding and Dickens. What distinguishes all three masters is their energy -- a yeasty and irrepressible bubbling- up of life. Like Dickens, especially, Malone cannot resist peopling his narrative with quirky souls who add nothing to the plot and everything to the texture of the novel. These "throwaway" characters, animated by the same appreciative spirit that produced the Aged Parent and Mrs. Jellyby, suggest a world of rapidly multiplying and largely benign eccentricity.

Handling Sin has none of the satiric edge of Malone's earlier novel Dingley Falls. Instead, Handling Sin is a larky tale that asks us to take its merry adventures at face value. We do, gladly. It's somewhat later, after the breakneck chases and the giggles have subsided, that we realize it's something wiser and deeper: the "holy adventure" Raleigh's father egged him on to. Handling Sin is pretty much the story of the Prodigal Son turned inside out, seen from the point of view of the stuffy, resentful "good" brother who stayed behind. It's a parable of love and reconciliation; It's also a celebration of plain old fun as one of God's great pedagogical devices. Funny, affable, and manageably sentimental, it's a delightful book.