Good

My world would be full of much less wonder and curiosity if it wasn't for the power of imagination. Oddly enough, my early love for books and knowledge was what pushed me forward to explore the world using my imagination not the indoctrination that I would eventually leave behind. My imagination pushed to me to continually ask questions for which religion had no answer. It still drives me to keep asking why and seeking out answers to those questions.

Imagination is a wonderful thing.

Nothing is inherently good or bad that cannot decide its own path.

gullibility fostered religion
curiosity fosters science
imagination is the genesis of art

Imagination in and of itself is an awesome thing, precisely because one gets to envision--and subsequently invent/create/discover/inspire--something into known existence that what wasn't there before. As a rule, I would say that if one imagines something destructive or applies it destructively (obvious example: death camps), it can be horrendous. When best applied, I think, is when one invention/discovery/paradigm spurs on further applications, be it in science, the arts, whatever.

Imagination is the one thing, I believe, without which humanity would never have risen above any of the other great apes.

If it wasn't for imagination I never would have made it through puberty....?

Not only in science but in arts as well. Everything has it's advantages and disadvantages.