Do you think humans should use their brains and reason to be the best they can be, instead of relying on religion? Then you believe in humanism.
Humanism comes from the Latin humanitas, which means "education that befits a civilized man." This belief system or cultural movement bubbled up during the Renaissance, promoting classical Greek and Roman values like reason, justice and ethics instead of supernatural religious ideas. People who follow humanism are called humanists, and they've probably studied a lot of literature, philosophy and history.