What does the Bible say about God's word lasting forever?

In Isaiah 40:8, the prophet declares a profound truth about the permanence of God's word, emphasizing that while earthly things like grass and flowers fade away, God's declarations are eternal. This reflects the total sovereignty and reliability of God’s promises. The word 'shall' indicates a certainty that transcends time, asserting that whatever God has spoken will surely come to pass. These promises are set in stone and form the foundation of our faith in the unchanging nature of God.