Ezra 8:21 Then I proclaimed a fast there at the river of Ahava, that we mght humble ourselves before our God, to seek from Him the right way for us and our little ones and all our possessions.

If you are not humble, you'll never see the need to fast. Fasting is a form humility, showing God that one need help from Him. You may display your strength to man, but always show your weakness to God if you desire to see His power manifested in your life. 

Ezra realized that without God's help, they will loose beyond their possessions, their lives is at stake. Elijah made a boast in the Lord that he heard the sound of rain, but he went up the mountain to ask God for mercy. He made a public announcement, but was not ashamed to pray even before his servant. He pressed in prayers until he got the needed result. 

Ezra 8:22 For I was ashamed to request of the king an escort of soldiers and horsemen to help us against the enemy on the road, because we had spoken to the king, saying, “The hand of our God is upon all those for good who seek Him, but His power and His wrath are against all those who forsake Him.” 23 So we fasted and entreated our God for this, and He answered our prayer.

God answer when we pray and ask for His help. You too can fast and pray to God on any matter, and you will be amazed at the help you will receive from Him, marvelous help.