Hijacked By Hasids : FICTION : THE HERE AND NOW,<i> By Robert Cohen (Scribner: $22; 352 pp.)</i>

We all get tired of living in the past, but apparently the past never tires of living in us,” says Sam Karnish, the narrator of Robert Cohen’s new novel, “The Here and Now.” This is a story about such conundrums, how the past is never really past but sticks around to haunt us, while the present flies by in a largely unreadable blur and is instantly consigned to history.

This richly comic and philosophical work focuses on the notion of tradition in an angst-ridden present. It interweaves the stories of three very different people: Sam Karnish, a single man struggling to make sense of his life, meets Aaron and Magda Brenner, a Hasidic couple, on a flight from New York to Houston. The result of that meeting is an unusual tale of love and obsession, a sort of boy-meets-girl-and-boy story set amid the cutthroat world of corporate New York and the Hasidic community of Crown Heights.

As a writer, Cohen seems drawn to triangular love stories. His highly regarded first novel, “The Organ Builder,” published in 1989, told the story of Herschel Freeman, a man who becomes involved with a couple who are making a film about his father, a scientist who worked on the first atomic bomb. The complex nature of the relationship among these three people provided a backdrop for a larger investigation into questions of love and morality in a post-nuclear America.

In “The Here and Now,” Cohen manages once again to capture a feeling of a mutable and frankly confused America, where ambition and desire have replaced faith and tradition. It is a land of rootless beings and a strangely secular place given its Puritan beginnings, a country where religion itself is an option few people feel a need to exercise.

Sam, a science editor at a New York news magazine, is one of those people who has little use for religion. He agrees with a friend who says, “People need an escape route, a trapdoor from the hard stuff. . . . All religion does is provide an aesthetic for intellectual surrender.” Born to a Jewish father and an agnostic socialist mother, Sam says of himself: “So I was not half-Jewish and half-something else, but half-Jewish and half-nothing. In short, an American kid.”

But that half-Jewish part of himself is about to be stirred up by the Brenners, much to his dismay. Sam knows little about their world: “All I knew of Hasids was that they were the old pious Jews you saw on television, or in sentimental plays on Broadway . . . or even now, in certain badly frayed sidepockets of the city. . . . You glimpsed them out of car windows, walking head down on narrow streets, incurious and remote in their medieval black coats, perpetually in a hurry, as if the modern world were one huge malign obstacle course and history itself was on their heels.” The Brenners may be pious but they’re not old, and in many ways they’re about to open Sam’s mind.

In truth, the modern world has become an obstacle course for Sam. His marriage has ended in divorce. His job is shaky. His girlfriend, Donna, with whom he has an on-again-off-again relationship, has had an abortion without telling him. He’s lonely and unhappy, but capable of such self-deprecating humor one can’t help but like him.

If Sam is the doubter, one who would like to believe but cannot, a weary rationalist dancing at the edge of faith and despair, Aaron is the other side of the coin, a secularist who has become a Baal Tshuvah--”Master of the Turning,” or one who has come back. He would like to see Sam do the same, and invites him to share a Sabbath meal with Magda and his in-laws.

Magda, the most enigmatic of the three characters, is the daughter of a rebbe, and knows little of the world outside Hasidism until Sam introduces her to it. She is also childless, due to Aaron’s sterility, and early on one suspects that the Brenners are looking to Sam to help them conceive a child.

For Sam, Magda exudes an attraction not based on physical beauty, but on something far more mysterious. She is a brooding, milky-skinned woman who “looks like she could catch cold easily,” yet her calm acceptance of life lends her an appealing strength. When Sam attends a bris with her, he finds himself “initiated into some new, unfathomable reality” and feels as if he is “the one who had just been born.” Later, their attempt at lovemaking fails and ends instead with a reenactment of a Sabbath ritual bath where desire of the flesh is transformed into spiritual immersion.

There’s a strength to Cohen’s writing that comes from the beauty of his language, from the rich scenes and a sense of strong characters caught in a crucible of change. He’s capable of serious philosophical inquiry, but he’s also a very funny writer. A perpetual, generic humor is one the novel’s most delightful aspects.

There is a word from the Kabbala, tsimtsum, which refers to the fact that during creation, to provide room for man and his freedom, God and his law retracted, leaving a little space, “like a father,” Cohen writes, who teaches his son to walk by leaving “a little space behind the boy, a little ambiguity. Maybe the boy falls down in that space, maybe not, it allows for a number of possibilities.”

The story of Magda and Sam and Aaron is like this, like tsimtsum. Cohen, the creator, gives us a story, as he did in his first book, that allows the reader the space to imagine different possibilities. He reminds us that “nothing goes away in nature, it just turns into something else.” We may deny our origins but we can never escape them. Or, as Magda says, “Some things you do because other people did them before you. The point is to keep things going.”