Cats need to scratch to shed their claws, mark their territory, and just indulge in their usual destructive tendencies that usually targets your valuable furniture. So if you want to protect your furniture, get a scratching post for your cat.
In fact, consider getting different types of scratching posts. The simplest is nothing more than a post. More sophisticated ones include a hammock or ledge, and the fanciest of all includes multiple levels and houses for a cat to play in.
Scratching posts are necessary to keep your cat happy so try getting different types to see which one your cat prefers. Chances are good that your cat will enjoy anything it can wreck, including everything in your house.