Churches grow when their members have been truly born again. They turned to God with a faith that was manifested by serving God, not self. This service was real, as opposed to artificial, because it was given out of worship and devotion to God, with a passion like they had served the idols of this world before being saved. This service was real because its goal was the promised appearing of the Savior who delivered them from the wrath to come. Here was labor that was energetically devoted, and eternity directed.
Churches grow when their members have the right motivation and objective to their labor.