Via Tim Challies. Good stuff here.
1. There is work to be done
Then he said to his disciples, “The harvest is plentiful, but the laborers are few; therefore pray earnestly to the Lord of the harvest to send out laborers into his harvest.”
2. Jesus has commanded you to do it
And Jesus came and said to them, “All authority in heaven and on earth has been given to me. Go therefore and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, teaching them to observe all that I have commanded you. And behold, I am with you always, to the end of the age.”
3. Success is guaranteed
And I have other sheep that are not of this fold. I must bring them also, and they will listen to my voice. So there will be one flock, one shepherd.
4. Jesus is the only salvation
Jesus said to him, “I am the way, and the truth, and the life. No one comes to the Father except through me.”
5. You were given the Holy Spirit for this purpose
But you will receive power when the Holy Spirit has come upon you, and you will be my witnesses in Jerusalem and in all Judea and Samaria, and to the end of the earth.
6. People won’t be saved without hearing
How then will they call on him in whom they have not believed? And how are they to believe in him of whom they have never heard? And how are they to hear without someone preaching? And how are they to preach unless they are sent? As it is written, “How beautiful are the feet of those who preach the good news!”
7. Evangelism is necessary for your own growth in Christ
And I pray that the sharing of your faith may become effective for the full knowledge of every good thing that is in us for the sake of Christ.