The main way that this novel shows creativity helping humans is that it provides an escape from their everyday lives, which are sometimes stressful and unhappy. Griet, for example, has a life of drudgery and hardship working for the Vermeer household. However, she finds an outlet in using the colorful vegetables to arrange patterns and pretty structures. Also, she enjoys looking at the colors and powders that Vermeer himself uses to create his paints. Her creativity is noticed by Vermeer, and because of it, he entrusts her with his studio. Cleaning his studio is a wonderful respite from having to be in the rest of the house, and his company provides her with interesting and stimulating conversation and thought. So, Griet's creativity provided her with an escape from her work and daily routine.
Vermeer's creativity also provided an escape. When painting, he was free from his wife's rather overbearing presence, and from the crazy chaos that was his household full of children. It was a way for him to have quiet, and to lose himselve in a different world.
Creativity is also seen in this book as a means for helping humans to have work. Vermeer earns his living based off of his creativity; that is definitely an example of creativity helping him. Griet, because of her creativity, is given a better position in the household. This helps her. Her father, before he lost his sight, used his creativity at painting tiles to earn her family's living. All throughout the book, creativity, when harnessed well, was a means for survival and wealth for the characters.
I hope that helped; good luck!