Zac Poonen addresses the persecution of God's prophets by the Pharisees, emphasizing that those who speak the truth often face hostility from those who prefer flattery over correction. He highlights the historical pattern of prophets being rejected and killed for delivering God's message, illustrating that offense taken from rebuke may indicate a Pharisaical heart. The sermon serves as a call to recognize and accept godly correction rather than resist it, as it is essential for spiritual growth.