"Then [Jesus] said to His disciples, 'The harvest is plentiful, but the laborers are few.' Therefore pray the Lord of the harvest to send out laborers into His harvest." --Matthew 9:37-38
Jesus communicates a problem.
"...'The harvest is plentiful,..." Most people interpret this to mean people are ready to come to God.
"...but the laborers are few'" This can be interpreted to mean there are not enough Christians to help them come near to God.
Jesus offers a solution.
"...pray the Lord..." will "...send out laborers..." We should not only make ourselves available to help others come to God, but we should pray for more Christians. Oswald Chambers (Bible teacher and author) says the prayer is labor!
Will you labor with me today in prayer for the laborers and the lost?
Lord, today we pray for [insert the names of people who need salvation]. Send laborers into their lives to help these people realize how much Jesus loves them and how He died for their sins. Once they have received salvation, send them as laborers for Christ to win more souls. Thank You for the gift of our salvation and that You have made us coworkers with Christ. In Christ's Name, Amen.
Further resources about praying for the unsaved can be found here: http://www.globalprn.com/wp-content/uploads/How-to-pray-for-unsaved-people.pdf
Read more of Oswald Chamber's commentary here: My Utmost for His Highest by Oswald Chambers