Therefore said he unto them, The harvest truly is great, but the labourers are few: pray ye therefore the Lord of the harvest, that he would send forth labourers into his harvest. Luke 10:2 KJV
We must not only pray, but go, or send, or both. When we go we are assured that the Lord is working with us.
And he said unto them, Go ye into all the world, and preach the gospel to every creature. He that believeth and is baptized shall be saved; but he that believeth not shall be damned.
And they went forth, and preached every where, the Lord working with them, and confirming the word with signs following. Amen. Mark 16:15-16, 20 KJV