How God chooses to use you is up to Him, but if you desire to be used by Him, you must make the choice to be a part of what He is doing. Walking into the unknown is scary; but when you think about it, living your whole life crawling around in the “dung” in the bat cave is much more scary.

http://who-god-is.com/dont-crawl-around-in-dung-when-fresh-green-leaves-are-just-yards-away