A.B. Simpson emphasizes our identity in Christ as 'strangers and pilgrims' in this world, highlighting that believers are chosen, elect, and called to a high and holy character. He explains that while we are to live in obedience and holiness, we must also maintain a childlike spirit, desiring spiritual growth and purity. Simpson further illustrates our roles as living stones in a spiritual house and a holy priesthood, called to represent God to the world. He warns against losing our separation from worldly influences, reminding us that our true home lies beyond this life. Ultimately, he encourages believers to live with a longing for their heavenly home, pressing forward in faith and obedience.