Chuck Smith emphasizes the distinction between two classes of people as outlined in Malachi 3:16: those who serve God and those who do not. He discusses the characteristics of God's servants, including their reverence for God, their conversations centered around Him, and their thoughts on His name. Smith highlights the results of serving God, such as being acknowledged by Him and spared from judgment. Ultimately, he challenges the congregation to reflect on which class they belong to and their desire to serve God wholeheartedly.