A.B. Simpson emphasizes the necessity of co-operating with the Holy Spirit, highlighting that while the Spirit operates sovereignly, He respects human free will and waits for our invitation to work in our lives. Simpson explains that receiving the Holy Spirit involves an active engagement, akin to consuming nourishment, and that being filled with the Spirit is a continual process of renewal and refreshment. He urges believers to trust, obey, and honor the Holy Spirit, recognizing His gentle guidance and the importance of responding to His voice. The sermon illustrates that our spiritual growth and effectiveness depend on how we utilize the gifts of the Spirit, drawing parallels with biblical parables. Ultimately, Simpson calls for a deeper relationship with the Holy Spirit, encouraging believers to expect His powerful presence in their lives.