"God could have taken the stars and illuminated the sky by spelling out "Jesus is alive!". Instead He left the responsibility to us ... to illuminate this area with our corporate life. Unbelievers see Jesus in His fullness through the collective life of His people practically joined together by His Spirit - the mystical (invisible) Body of Christ becomes visible for all to see.
In the early church, a kind of rhythm of life was evident in which Christians gathered together daily to love, serve, instruct, pray and personally care for one another. Then they would go out into the world again to let the warmth and glow of their love-filled lives overflow into a spontaneous Christian witness that draw love-starved unbelievers.
The concern of Christians for each other left the doubting world drooling with envy. It prompted the much-quoted remark of a pagan writer, "How these Christians love one another".
Larry Tomczak and C J Mahaney - "Gathering of Believers Family News" - July 1977.