I LOVE The Host. And I actually wrote a blog post about this a while ago so I’mma steal some from that:
Stephenie Meyer basically found the perfect situation to expose every facet of human nature, good and bad. The alien Wanderer, later referred to as Wanda, is fundamentally gentle and self-sacrificing, while her human host Melanie (reduced to a voice in Wanda’s head) is passionate and violent. Melanie stirs things in Wanda that, as a peace-loving soul, she shouldn’t feel, while Wanda’s kindness and courage earn her Melanie’s frustration and eventually respect.
What really makes it a petri dish of humanity is each human’s reaction to the alien presence. Some treat her as an enemy who’ll endanger their small colony. Others warily accept her. Some can’t figure out how to distinguish Wanda’s consciousness from Melanie’s, but others can tell exactly which one is in control.
Wanda slowly learns that the human tendency toward extreme emotions like violence also allows them to feel love more deeply than any other species she’s encountered. The same love for his makeshift family that motivates Ian to try to kill Wanda also drives him to protect her when he realizes that she’s a person too. Doc’s need to heal forces him to commit atrocities against Wanda’s people. Jared’s love for Melanie prompts his hatred for the alien that took her away.
It takes an alien to make the scattered survivors realize what it means to be human. Through Wanda, we see that the ugliness of humanity is tied inextricably with what makes humanity beautiful.
Also, the ending is one of the most satisfying endings I’ve ever read, mostly because Wanda has to fight tooth and nail every step of the way to get it. She earns her ending, and in every way it’s perfect, poignant and wonderful.
ALSO, Wanda’s story has a lot of parallels with Castiel’s. He’s an angel that fell for humanity and she’s an alien that basically does the same thing. So if you dig that narrative and you want to see the youngest Winchester boy being a freaking ADORABLE LOVING SAINT, you should totally go see it. And read it. It’s AWESOME.