We are all called to serve, but is God really served? Where lies the secret of true service? Paul declared, God is my witness Whom I serve in my spirit (Rom. 1.9). Clearly the secret of service is to serve in spirit. Does this sound simple? It, nonetheless, requires much dealing from God. In this present volume, brother Watchman Nee shared with us what he had learned through the years of his serving God. He delivered these messages towards the latter years of his freedom. These are fundamental and essential to true service. May all who truly desire to serve God to His satisfaction learn this open but neglected secret.