Answer:
I am a box that holds keys without locks, yet they can unlock your soul.
Often held but never touched. Always wet but never rusts. Often bits but seldom bit. To use it well you must have wit.
There are millions of me. I am very small but when moving fast I am deadly.
I can travel from there to here by disappearing, and here to there by reappearing.
Screaming, soaring seeking sky. Flowers of fire flying high. Eastern art from ancient time. Name me now and solve this rhyme.
People take me on walks and I run and have fun. What am I?