George Whitefield on Praying Before, In and After a Sermon

 If you would receive a blessing from the Lord, when you hear His Word preached, pray to Him, both before, in, and after every sermon, to endue the minister with power to speak, and to grant you a will and ability to put in practice, what He shall show from the Book of God to be your duty.  This would be an excellent means to render the word preached effectual to the enlightening and enflaming your hearts; and without this, all the other means before prescribed will be in vain.  No doubt it was this consideration that made St. Paul so earnestly entreat His beloved Ephesians to intercede with God for Him: “Praying always, with all manner of prayer and supplication in the spirit, and for me also, that I may open my mouth with boldness, to make known the mysteries of the gospel.”  And if so great an Apostle as St. Paul needed the prayers of His people, much more do those ministers, who have only the ordinary gifts of the Holy Spirit.

    Besides, this would be a good proof that you sincerely desired to do, as well as to know, the will of God.  And it must highly profit both ministers and people, because God, through your prayers, will give them a double portion of His Holy Spirit, whereby they will be enabled to instruct you more fully in the things which pertain to the kingdom of God.