Think about training. Athletes train. Pilots train. Soldiers train. Kids have training wheels on their bikes. Training is a word that translates into our culture for discipleship. Training in disciplines of life, training in a way of life; the way of life that Jesus taught.
In the great commission passage in Matthew, Jesus says to go out and make disciples-----> Train people in what you know, that was passed down from Jesus. That's what he tells his followers to do. Jesus didn't say to go plant churches. Churches are the result of groups or gatherings of people in training.