Here's an example of what I mean about the importance of learning from other contexts. It's taken from a case study of a church planting movement in India. The author is a cross-cultural missionary whose job it is to empower and partner with nationals. He writes,
In one case, I was training a group of 10 Hindu background believers in T4T. They came back after the training and reported 30 Hindus high caste Hindus had come to Christ. This was exciting in itself, but what happened next was incredible. I told them that when we meet next time we would not discuss who they had led to Christ. We would only discuss who they led to Christ and had trained to share their story and helped them in telling others of Christ.
When they came back they reported that those 30 new believers had led 270 people to Christ, including those who the new believers taught also to share their faith who in turn led others to Christ. This is where evangelism turns from addition to multiplication.
I told these Hindu background believers that I do not see two hundred new believers, I see a whole people touched by the gospel as you train all new believers to share Christ and they in turn also share Christ following up these new believers growing in the word in participative Bible studies and starting multiplying house churches. If you live this vision, I told them, the Gospel will cover your people (of twelve million) like the waters cover the sea.
Contexts can vary but biblical principles don't.