Answer:
I am a box who holds keys but not locks. With the right combination I may unlock your soul
In all the world none can compare I am a tiny weaver my deadly cloth so silky and fair.
What can fill a room but takes up no space?
I tremble at each breath of air and yet can heaviest burdens bear.
What asks but never answers?
No matter how little or how much you use me, you change me every month.