Jessie Penn-Lewis emphasizes the critical distinction between the soul and spirit, arguing that many Christians lack understanding of this difference, which hinders their spiritual growth. She explains that the soul serves as a medium between the spirit and body, and that the fall of man has led to a confusion where the soul often dominates the spirit. Penn-Lewis highlights the importance of the Holy Spirit in teaching believers this distinction, enabling them to experience true spiritual understanding. She warns that without this knowledge, Christians may be deceived by false imitations of spiritual life. Ultimately, she calls for a return to the biblical understanding of man's tripartite nature to restore proper order in spiritual life.