Multiplication
"Multiplication" is the key component - not just winning people to the Lord one-by-one (addition). But training those won to the Lord to win, and then train, others. In the Book of Acts we read that the disciples "multiplied" and "multiplied exceedingly."
The Ministry
-
On-the-job training
On-the-job training is another vital ingredient. By actually going out with experienced trainers in real life witnessing situations, people learn how to share their faith. Much like learning to fly an airplane would be impossible without actually getting in the cockpit, evangelism is difficult without leaving the confines of a classroom.