Though it might sound obvious, it's important to remember that Dungeons and Dragons is a game about fantasy. Yes, this usually means 'fantasy' in the sense of an otherworldly realm with Tolkein-esque ...
Unless we have a Bear Totem Barbarian to deal with, Rage will only give your player resistance to three damage types: bludgeoning, piercing, and slashing. In other words, if you want to hit them ...