As we pray, our faith should allow for God's answer to come at a time and in a manner in which we may not expect. God sees the big picture. His sight is not limited by the things that hinder our perspective. His wisdom goes far beyond our capacity. He knows of answers that surpass our longings.
As we pray, our faith should allow us to realize that God's silence is often intentional and that "unanswered" prayers are still heard by God. God may be silent to test the maturity of our faith, or to cause us to reevaluate our prayers in the light of his will. And, God's silence may be his answer.
As we pray, our faith should motivate us to be persistent in bringing our petitions before God. God is not hard of hearing, but in our persistence our trust in God's response is affirmed and our prayers may become refined through the repitition in which we offer them.