Our Scripture reading today is Matthew 9:36-38.
Verse 38, "Pray ye therefore the Lord of the harvest, that he will send forth labourers into his harvest."
The true work of evangelism has already started before the Gospel is presented one time.  Are we praying for our unsaved family member?  Are we praying for our unsaved co-worker?  Are we praying for more men and women to answer God's call to be missionaries?  The Lord Jesus challenges His disciples in Matthew 9 to be people of prayer.  We must PRAY for more labourers to go with the Gospel.  We must also be the answer to that prayer and GO!  It all starts with prayer!
The follow is taken from The Place of Prayer in Evangelism (1910-1915) by R. A. Torrey:
The history of the Church demonstrates beyond a question that the most important human factor in the evangelism of the world is prayer. The great need of the present hour is prayer. In our work at home and abroad we are placing more and more dependence upon men, machinery, and methods, and less and less upon God. Evangelism at home is becoming more and more mechanical, and methods are being resorted to that are more and more revolting to all spiritually minded people; while evangelism abroad is becoming more and more merely educational and sociological. What is needed above everything else today is prayer, true prayer, prayer in the power of the Holy Ghost, and prayer that meets the conditions of prevailing prayer so plainly laid down in the Word of God.  
Prayer is STILL the great need of the hour!