Isaiah 40:31 in the King James Version says, “But they that wait upon the LORD shall renew their strength; they shall mount up with wings as eagles; they shall run, and not be weary; and they shall walk, and not faint.”

This verse belongs to a chapter written to a people who had grown tired in spirit and tempted to believe that God had forgotten them. Isaiah 40 speaks into discouragement, delay, and the feeling that one’s way is hidden from the Lord. Just before this promise, the chapter declares that even the strongest human strength fails: “Even the youths shall faint and be weary, and the young men shall utterly fall” (Isaiah 40:30). The point is not merely that life is hard, but that natural vigor, competence, and willpower—what people lean on when they try to carry themselves—cannot finally bear the weight of suffering, waiting, and long obedience. The verse then turns with “But,” setting the Lord as the decisive contrast to human limitations. Where human strength collapses, divine strength is not only sufficient but renewable.

“To wait upon the LORD” in KJV language is not passive idleness. It is the posture of faith that stays oriented toward God instead of fleeing into self-reliance, panic, or despair. Waiting includes trust, prayer, obedience, and a refusal to take shortcuts that would violate God’s ways. It is a kind of spiritual dependence that admits, in practice and not only in words, that the Lord is the source of help and the keeper of timing. In the broader context of Isaiah 40, the Lord is presented as incomparable in power and wisdom, the Creator who “fainteth not, neither is weary” (Isaiah 40:28). Waiting is therefore grounded in who God is: if the Lord does not tire and does not lose understanding, then the one who waits is not clinging to wishful thinking but anchoring to a reality stronger than the circumstances.

The promise that follows—“shall renew their strength”—speaks of an exchange and a restoration. The verse does not say they will discover hidden reserves within themselves; it says their strength will be renewed as a gift, replenished from the Lord. The theme here is not heroic self-improvement but grace given to the weary. Renewal implies that strength can be spent and truly depleted; the faithful are not shamed for exhaustion. Yet it also implies that depletion is not the end of usefulness, hope, or movement forward. God’s provision is not a one-time burst but a continuing renewal, fitted to seasons of strain.

The next image, “they shall mount up with wings as eagles,” is symbolic and rich. “Mount up” suggests rising above what would ordinarily press a person down. Wings in Scripture commonly signify protection and deliverance, but here they also signify lift—an ability to ascend that does not come from sheer effort. The eagle, in KJV diction, represents strength, height, and freedom of movement in the skies, a creature that seems to ride the wind rather than be mastered by it. The symbolism is not that believers become untouchable, but that the Lord gives a capacity to rise in perspective and endurance, to be carried through what would otherwise overwhelm. It is a picture of elevated hope and spiritual resilience, of being enabled to do what is beyond natural reach.

Then Isaiah 40:31 turns from soaring to steady progress: “they shall run, and not be weary; and they shall walk, and not faint.” This pairing is significant. Running evokes seasons of urgent demand, intense exertion, and long stretches of labor when the pace is fast and the load is heavy. Walking evokes ordinary life, the daily steps that can feel monotonous, slow, or unglamorous. The verse promises God’s sustaining power in both. It is not only for dramatic moments of deliverance, when one “mounts up,” but also for the prolonged responsibilities and unseen faithfulness of “running” and “walking.” The repetition of not being weary and not faint does not mean the believer never feels tired; rather, it means the believer is preserved from collapse, from a weariness that ends in quitting, despair, or spiritual failure. The Lord’s renewal meets both the crises that demand speed and the long routines that demand patience.

In the larger sweep of Isaiah 40, this verse is meant to restore confidence in God’s character. The chapter insists that the Lord measures waters, weighs mountains, and calls the stars by name; therefore, the one who feels small and spent is invited to interpret life through the greatness of God rather than through personal weakness. The significance of Isaiah 40:31 is that it redefines strength as dependence and endurance as a gift. It teaches that waiting is not wasted time but the place where God’s people are made capable—lifted to hope like an eagle, sustained to labor without collapse, and kept to continue step by step without fainting—because the Lord Himself is the unwearied source of their life.