“Missionaries, evangelists, and teachers who have understood both the scandal of the cross and the irreplaceable and foundational significance of of the news of Jesus the crucified and risen Messiah and Savior will not rely on strategies, models, methods, or techniques. They rely on the presence of God when they proclaim Jesus Christ, and on the effective power of the Holy Spirit.
This dependence on God rather than on methods liberates them from following every new fad, from using only one particular method, from using always the same techniques, and from copying methods and techniques from others whose ministry is deemed successful. Preachers of the gospel who understand that the primary cause of people coming to faith in Jesus the crucified Savior and Lord is the power of God become truly flexible, able to become a Jew for Jews and a Greek for Greeks.
They are authentically flexible because they are motivated not by the pressure of demonstrating the ‘effectiveness’ of their methods or the ‘success’ of their ministry but by their commitment to God and by their commitment to the people they seek to reach with the news of Jesus, a twofold commitment that is characterized by sacrificial love, faith and hope.”
Eckhard J. Schnabel, Paul the Missionary: Realities, Strategies and Methods p. 404 (paragraph breaks added)