Despite Stewart's inexperience, his creativity and refusal to give in quickly makes him able to stand up to some of Green Lantern's most dangerous enemies.

Source: https://www.cbr.com/green-lantern-best-forgotten-comics/

Every Green Lantern has shown the ability to resist fear, which is extremely important because the Green Lantern's natural enemies are the Yellow Lanterns, who are empowered by fear.

Source: https://screenrant.com/nightwing-green-lantern-worthy-overcome-fear/