G.W. North emphasizes the significance of spiritual fruitfulness in the life of believers, drawing parallels between marriage and the union with Christ as essential for producing fruit unto God. He highlights that just as childlessness was seen as a reproach in ancient times, a lack of spiritual fruit is a serious concern for the Church, which is called to be united with Christ and fulfill God's desire for many children in faith. North illustrates this through the stories of barren women in the Bible, such as Sarah, Rachel, and Hannah, who exemplified deep longing for fruitfulness, reflecting God's heart for His people. Ultimately, he asserts that true life in Christ is marked by the bearing of spiritual fruit, which is the evidence of a vibrant relationship with God.