The lie is a major tool in the writer’s workbox. Often it turns the plot a full one eighty degrees. Sometimes it drives the whole story. Think of de Maupassant’s The Necklace.
But for a lie to work in a novel, you have to have a convincing liar. By that I don’t mean someone who is habitually economical with the truth. I mean someone who has a good reason to lie and does so. And, even more important, someone whom another person, or even many people, will believe.