After God calls Gideon to be the warrior-leader of Israel who will lead Israel out of oppression and validates this by the display of signs (at the request of Gideon), God decides to whittle down the number of his troops, but tells him why.
"In order that Israel may not boast against me that her own strength has saved her, announce now to the people, 'Anyone who trembles with fear may turn back and leave Mount Gilead.' " So twenty-two thousand men left, while ten thousand remained." (Judges 7:2-3)
Wow! Thirty-two thousand fighting men were at Gideon's disposal!  Then twenty-two thousand were allowed to go home simply on the basis of "anyone who trembles with fear".  Guess God doesn't want pansies in His army (another message there)!
But Wait There's More!

"But the LORD said to Gideon, "There are still too many men. Take them down to the water, and I will sift them for you there. If I say, 'This one shall go with you,' he shall go; but if I say, 'This one shall not go with you,' he shall not go."  So Gideon took the men down to the water. There the LORD told him, "Separate those who lap the water with their tongues like a dog from those who kneel down to drink."  Three hundred men lapped with their hands to their mouths. All the rest got down on their knees to drink.  The LORD said to Gideon, "With the three hundred men that lapped I will save you and give the Midianites into your hands. Let all the other men go, each to his own place." (Judges 7:4-7)
300 - sounds like a good movie about small odds/amounts defeating overwhelming odds/amounts of soldiers.  Oh, wait, it is a movie.  Wrong era and wrong people for this 300.  If I was Gideon, my confidence would be a little shaky about now.  BUT GOD knows all of us personally, including Gideon, and says,  

"'If you are afraid to attack, go down to the camp with your servant Purah and listen to what they are saying. Afterward, you will be encouraged to attack the camp.' So he and Purah his servant went down to the outposts of the camp." (7:10) 

Gideon must have been afraid because he went down to the camp.  I would be too.  Especially seeing that I have 300 soldiers now, instead of the 32,000 I started out with and the enemy - "The Midianites, the Amalekites and all the other eastern peoples had settled in the valley, thick as locusts. Their camels could no more be counted than the sand on the seashore." (Judges 7:12)  In today's lingo I can hear Gideon saying something like this....

Gideon is finally starting to get a little hmph, a little get-up in his get-up-and-go.  However, this increases when Gideon hears a dream of the enemy and it's interpretation that confirms God's hand in this matter and Gideon as the warrior-leader of little Israel.

Take Away:  The Lord knew what was needed for Gideon to follow through and for Israel's faith to flourish for a season.  God shared His strategy of faith-building for Israel with Gideon by explaining the "whittling process" of the troops.  God also supplied the means by which Gideon could personally get over the "fear hump" by instructing him to listen to the dream and interpretation of the very enemy he was to face.  Another way in which God supplied the "push" over the Fear Factor was to provide Gideon with a support team.  Gideon had his servant Purah and 300 men to witness to the dream and the interpretation of the victory yet to come. You really start relying on each other when the size of the group is relatively manageable. The Holy Spirit knows what we need in our daily lives. He knows what is needed for His plan(s) to be accomplished in our lives. Even in the face of tough circumstances God has been there, done that, has the t-shirt, and in fact has a new victorious t-shirt for us to wear! "For we do not have a high priest who is unable to sympathize with our weaknesses, but we have one who has been tempted in every way, just as we are--yet was without sin." (Hebrews 4:15)  My favorite verse in the Bible (besides the standard John 3:16).