How do we know God's Word does not fail?

In Romans 9:6, Paul reassures us that God's Word has not fallen to the ground or lost its effectiveness, despite the rebellion of Israel. The certainty of God’s plans and promises is evident in verses like Isaiah 55:10-11, where God declares that His Word will accomplish what He pleases. This is crucial to understanding God's sovereignty; He cannot lie and His purposes are always fulfilled. Therefore, believers can trust that God's declarations will come to fruition, reassuring us of His faithfulness.