Profound words and compelling philosophy exist all throughout Naruto. Even though it's been some years now since the ending of the original series, many fans can still quote powerful lines from characters by heart. These lines somehow manage to attach themselves to the mind and are never forgotten, like Kakashi's lesson about never abandoning a friend, Itachi's monologue about the nature of reality or Madara's speech about the cruelty of the world. Quotes like these capture the major themes of Naruto and reveal key details about the characters they come from. But there is one quote from the Demon of the Hidden Mist himself, Zabuza Momochi, that represents the entire series holistically.
"You may be right...a shinobi is still a human...we may not be able to become emotionless tools..."
Zabuza's quote is the most powerful not just because it sets up one of the key themes of Naruto, but also because it challenges the audience's assumptions as well. When people think of ninjas, they often imagine heartless killers dressed in dark clothing that move in silence -- and they wouldn't necessarily be wrong. Many characters in the world of Naruto are exactly that, such as Zabuza, Itachi and Madara. These characters represent what a ninja is supposed to be. However, Naruto Uzumaki is the opposite of that. He's loud, colorful, and cares about both his allies and enemies. He is more human than an emotionless tool.
In the first arc of the series, many characters try to teach Naruto that to be a good ninja, he must cut out his emotions. Zabuza shows him that a ninja must be able to kill without mercy. Haku tells him that showing sympathy to an enemy could lead to his own death or that of an ally. Kakashi reinforces this at the end of the arc by telling Naruto that these same rules apply to the Leaf Village. A ninja must do what they are asked without question or feeling. Naruto learns what a perfect ninja is and what he is supposed to become, but refuses to do so. Instead, he decides to do things his own way and become the ninja that he wants to be. Naruto chooses to maintain his humanity.
Throughout the rest of the series, Naruto continues to face opponents who have tried to abandon or suppress their humanity in order to become a better ninja or achieve their goals. At each point of conflict, Naruto has to decide if he's going to become like them or stick to his ninja way. Enemies like Gaara, Sasuke, Nagato, Obito and Madara all tried to cut all personal ties with the people they cared about, as well as their own humanity, to become stronger.
The cruelty and suffering in the world taught these characters that friends, love and kindness are all burdens that hold people back from their full potential. However, instead of becoming like them and abandoning his friends, Naruto fights for the people he cares about and wins. He never acts out of cruelty or for revenge. This show of compassion restores many of these characters' humanity, eventually turning them into allies.
Zabuza's quote is so important because it proves that it's impossible for a ninja to become an emotionless tool. A ninja can suppress or ignore their humanity, but they can never get rid of it. Even Zabuza, a self-proclaimed demon who slaughtered his entire academy class, still shed tears of grief over Haku's body. He was still human. This event teaches both Naruto and the audience that a person doesn't have to compromise their morals or emotions to be great or strong. In fact, being human and creating strong bonds with the people you care about is exactly what makes someone great.
