praying for preaching

"It is of no use for me to preach to the people, my dear Christian brothers and sisters, unless you pray for them. It is of no use holding special services for the quickening of the spiritually dead unless the Holy Spirit is brought to them by our prayers. It may be that you who pray have more to do with the blessed results than we who preach." (Charles Spurgeon from a sermon in 1868 called Prayer-Meetings)