A.W. Tozer emphasizes the importance of being willing to hear the voice of God, reflecting on the historical rejection of prophets and wise men sent by God. He highlights Jesus' lament over Jerusalem's unwillingness to accept divine guidance, illustrating the consequences of ignoring God's call. Tozer also references the wisdom of Proverbs, which warns against the folly of rejecting God's rebuke and the resulting calamity. The sermon challenges listeners to examine their openness to God's voice and the implications of their response. Ultimately, it calls for a heart willing to listen and respond to God's wisdom.