The speaker reflects on his mother's question, "What lack we yet?" drawing from a biblical story in Acts 19. Apollos, a knowledgeable Jew, lacked understanding of the Holy Spirit, which Aquila and Priscilla explained to him. Paul later found disciples in Ephesus who knew only John's baptism of repentance, not the Holy Spirit. Paul questioned them, revealing their lack. After Paul laid hands on them, they received the Holy Spirit, enabling them to speak in tongues and prophesy. The speaker emphasizes the importance of the Holy Spirit in Christian life, suggesting many modern assemblies lack this vital experience, leading to carnal Christian lives and potential negative impacts on church leaders.