James 1:5

If any of you lacks wisdom (to guide him through a decision or circumstance), he is to ask (our benevolent) God, who gives to everyone generously and without rebuke or blame, and it will be given to him. But he must ask in faith, without doubting for the one who doubts is like a billowing surge of the sea that is blown about and tossed by the wind. 

Recognize doubt when it tries to infiltrate the faith and kick it out. Go to the verses and repeat them until the dart of doubt from the devil is gone. God is faithful and honors His Word, and we must stand by the Word in faith until the answer comes.