Depending on how much if it is magic and how much if it is actually lightning, it's easier then one might think. A lot of lighting's strength comes from being a very souped up concentration of heat (hence why fire benders can do it), but anything with good heat conductivity can withstand lightning. Many earth metals for example, and perhaps to the surprise of some, water in its purest form is actually immune to electrical currents like lightning since there aren't any charged particles for eletricty to travel through.
Lightning certainly has its utility, but a lot of people seem to think of it as a glorified laser cannon. And there are plenty of ways to counter it if you know what it actually does.