The sermon was based on the New Testament verses of Matthew 7:7-8.
The familiar words spoken by the Lord Jesus Christ--and that speak of persisent prayer--appear towards the end of his famous Sermon on the Mount:
Ask and it will be given to you; seek and you will find; knock and the door will be opened to you. For everyone who asks receives; the one who seeks finds; and to the one who knocks, the door will be opened.
To listen online to the audio of the 50-minute sermon preached at Grace Church in my native West Hartford, Connecticut, click here or here (see 9/11/2011 date).
Grace Church (est. 2005) is pastored by Dr. Ted Bigelow, author of the recently released (January 2011) The Titus Mandate: Rescue, Protect, Reform (Paul's Plan That Rescues Christians From Dangerous Churches).
NOTE:
Just weeks after 9/11 took place, I preached a message from the Old Testament passage of Isaiah 55:1-13. The October 2001 sermon occured at Joyce Bible Church in Joyce, Washington.
If interested in a free audio CD of the message, contact Uncommon Christian Ministries.