Judges 6:15 “But Gideon replied, “Sir, how can I save Israel? My family is the poorest in the whole tribe of Manasseh, and I am the least thought of in the entire family!” 

There are many instances in the bible we see accounts where God chooses men who he set apart from the beginning of time. Set apart without knowledge to them of who they will become. I believe God withholds this knowledge to prove a point. Not only does he withhold the knowledge but most times he allows these chosen leaders to not live a life that is an easy one. These chosen leaders usually have a rough time, never seeing themselves as anybody worthy of a leadership position (except Joseph who He gave dreams about his future and David who was anointed from a boy).  These chosen leaders encountered many challenges, they were sometimes reduced to nothing and stripped of their self-confidence. I believe God does this to prove a point.
The point is that we can do nothing of ourselves. The point is that, he strips us of self-confidence and replaces that with Spiritual confidence so that at no point we or anyone else can believe that all things are possible through us alone or that we are in control.

Gideon exclaims in Judges 6:15 “Sir, how can I save Israel? My family is the poorest in the whole tribe of Manasseh, and I am the least thought of in the entire family” and the lord replies “But I, Jehovah, will be with you! And you shall quickly destroy the Midianite hordes!”

Is God calling you today to do something mighty and you are questioning yourself. Go ahead and question, but understand that we do nothing on our own accord. God who calls us, equips us mightily and gives us Spiritual confidence because he knows we can never do what he calls us to do with our self-confidence.