What does Isaiah 26:18 mean?
Isaiah has compared Israel's anguish under God's discipline to the pain endured by a pregnant woman as she gets closer to giving birth. This pain increases with each new contraction, bringing the woman to sob as it grows more intense. Isaiah has been clear: The Lord brought this pain on Israel in increasing amounts because of their unfaithfulness to Him (Isaiah 26:16–17).Now Isaiah changes the metaphor slightly. For the woman giving birth, all the pain and distress is set aside once the birth is completed and a new life begins. The pain is replaced by joy and partially forgotten (John 16:21). We may expect Isaiah to say the same about Israel's discipline and eventual repentance. The pain of the Lord's discipline is replaced by the joy of being restored in relationship and receiving His blessings once more. This is a good analogy, but it's not the one that Isaiah uses in this passage.
Instead, he explains that of that distress in Israel under the Lord's discipline yields nothing meaningful in the end. Unlike the woman who gives birth to a baby, Israel's agony resulted only in giving birth "to wind" because of their faithlessness to the Lord. Repentance may lead to restoration, but that specific generation lost the opportunity to accomplish the mission given by God (Numbers 14:26–32).
If Israel had been faithful to the Lord, He would have continued to bless them in all the ways that He promised (Deuteronomy 28:1–7). This would include victory over their enemies and becoming the source of ultimate blessing to all the earth (John 4:22). Instead, Isaiah laments that his people have not accomplished the deliverance of the world. This deliverance, he believes, could have come from their obedience to the Lord. The wicked, idol-worshipping nations of the earth have not fallen before them because Israel did not keep their covenant with God.
It is important to remember that God still accomplished His purpose on earth. Through Christ, He still brought blessing to the nations through Israel (Acts 1:8). The Lord will still bring final justice to all the earth's wickedness. God's purpose is never thwarted by human failure. Instead, Isaiah seems to be saying that his generation missed the opportunity to be directly used by the Lord to accomplish His will (Numbers 14:20–23). They missed the chance to bring about God's justice, and to experience His full blessing. Chasing foreign gods and rebellion against the Lord resulted in the world turning as it always had, without the full blessings of the Lord.
Those who know the Lord through faith in Jesus face similar opportunities and consequences. It is possible for us to belong to Him but to waste our chance to participate in accomplishing His good in the world. Peter described those who stop growing as being ineffective and unfruitful (1 Peter 1:8–11). We can live as if we have forgotten our own forgiveness through the blood of Christ. The result is not lost salvation; it is wasted time this side of eternity (1 Corinthians 3:15).
However, salvation will come for those who belong to the Lord and have died (Isaiah 26:19).