The New Testament method was admirably adapted for the establishing of independent congregations. It insisted upon making the local church directly dependent upon the Holy Spirit. That produced, in the shortest possible time, experienced leadership. It set every convert to work immediately using the gifts of the Spirit given to him for service. Responsibility was thrust upon the churches and they were forced to function. They were revisited when necessary to give them encouragement and instruction but, so long as all went well, the Evangelist took no responsibility for their direction or work. If anything went wrong, effective aid was given at once, and the spiritual order restored, but never did an Evangelist consent to remain permanently with a church.
This method required a very real and active faith on the part of the Evangelists. They had to believe that the Holy Spirit could and would do His work in and through the converts. To a great extent, [the modern] method is the outcome of lack of faith; we fear that the Holy Spirit will not be able to do His part until we have made the way easy for Him. The New Testament Evangelists had their eyes upon God and upon His power and faithfulness; what looms large to us is rather the unpromising nature of the material to be used. We find it hard to believe that God can do for them what He did for similar converts in New Testament times, and what He has done even for us.
—Alex Rattray Hay (Early 20th Century Scottish Missionary, from Hay, The New Testament Order for Church and Missionary, Wipf & Stock Pub., 396-97)