“It is impossible to spend several months in close study of the remarkable short book, conventionally known as the Acts of the Apostles, without being profoundly stirred and to be honest, disturbed. The reader is stirred because he is seeing Christianity, the real thing, in action for the first time in human history. The newborn church, as vulnerable as any human child, having neither money, influence nor power in the ordinary sense, is setting forth joyfully and courageously to win the pagan world for God through Christ. The young Church, like all young creatures, is appealing in its simplicty and single-heartedness. Here we are seeing the Church in its first youth, valiant and unspoiled -- a body of ordinary men and women joined in an unconquerable fellowship never before seen on this earth.
Yet we cannot help feeling disturbed as well as moved, for this surely is the Church as it was meant to be. It is vigrorous and flexible, for these are the days before it ever became fat and short of breath through prosperity or muscle-bound by over-organisation. These men did not make "acts of faith," they believed, they did not "say their prayers," they really prayed. They did not hold conferences on psychosomatic medicine, they simply healed the sick. But if they were uncomplicated and naive by modern standards we have ruefully to admit that they were open on the God-ward side in a way that is almost unknown today.
No one can read this book without being convinced that there is Someone here at work besides mere human beings. Perhaps because in their very simplicity, perhaps because of their readiness to believe, to obey, to give, to suffer, and if need be to die, the Spirit of God found what surely He must always be seeking - a fellowship of men and women so united in love and faith that He can work in them and through them with the minimum of let or hindrance. Consequently it is a matter of sober historical fact that never before has any small body of ordinary people so moved the world that their enemies could say, with tears of rage in their eyes, that these men "have turned the world upside down"! (Acts 17:6)
J.B.Phillips: Preface to "The Young Church in Action"