Why the Halfling?

Gandalf Teaches Galadriel an Important Lesson

Galadriel: Mithrandir, why the halfling?

Gandalf: I do not know. Saruman believes that it is only great power that can hold evil in check, but that is not what I've found. I've found it is the small things, everyday deeds of ordinary folk that keeps the darkness at bay; simple acts of kindness and love. Why Bilbo Baggins? Perhaps it is because I am afraid, and he gives me courage.

Galadriel: Do not be afraid, Mithandir. You are not alone. If you should ever need my help, I will come.