Matthew Chapter 9

Mat 9:37 Then saith he unto his disciples, The harvest truly is plenteous, but the labourers are few;
Mat 9:38 Pray ye therefore the Lord of the harvest, that he will send forth labourers into his harvest.

Often this verse is used to express how less workers there are in church and that many more are needed. But we shouldn't just pray and wait. Of course praying is not wrong. But praying ALONE is not enough (like when you are praying and fasting 2 weeks before a test, hoping that God will tell you all the answers during the test; but indeed you have to pray (maybe fast) AND learn for the test). So actually we are supposed to be the workers, that work, so that there may be more and more workers. And our work (increasing the number the workers= preaching the gospel) can only be accomplished by prayer and our will to work.