One of the most exhilarating thoughts contained in the bible is found in the fortieth chapter of Isaiah. Within the page are just a few words, but they paint a most vibrant and thrilling picture that stimulates the imagination of the mind: “They that wait upon the LORD shall renew their strength; they shall mount up with wings like eagles” (Isaiah 40:31).
The eagle is the stateliest of all birds, having about 7,000 feathers, and standing over 3 ft. tall with an impressive 7 ft. wing span. It comes as no surprise that man has always had the dream to fly like an eagle, just to mount up and take off into the heavens, soaring through the sky effortlessly with speed, grace, and stealth. Oh the rejuvenation that would bring! Yes, and that is exactly the feeling that is produced within the soul of “they that wait upon the LORD.”
The context around Isaiah 40 will show us that God’s people were currently captives of the Babylonians and were growing faint day after day. Their hope for help was diminishing and they were saying “my way is hidden from the LORD, and my just claim is passed over by my God” (v. 27). It is at this point when God reminds them who He is and what He can do: “The everlasting God, the LORD, The Creator of the ends of the earth, neither faints nor is weary. His understanding is unsearchable. He gives power to the weak, and to those who have no might He increases strength” (v. 28-29). The God who has always lived and created the ends of the earth, and sustains all things with His might, has yet to ever become weary, for it is impossible for Him to do so. It is with His power beyond comprehension that He can also give strength to the weak. But how? How can the weary receive such strength? They must “wait upon the LORD” in order to “renew their strength.”
Sometimes waiting for something or someone can quickly become a weariness to the flesh, but not when one waits on God, for they that wait on God know that He is faithful to His servants and His favor will be manifested to them. Waiting on God means to wait for His help, to trust in Him through the difficult days. This was the trouble with the captives in Babylonia, they were growing faint, their hope for God’s help had departed and therefore they had no more strength; their faith had failed. So Isaiah exhorts: “they that wait upon the LORD shall renew their strength.” The Hebrew word for renew means to spring up, or sprout again as grass. What a promise that was for these fainting captives! They could be fresh again like the vibrant blade of grass that sprouts up from the dreary lifeless dirt. As encouraging as that sounds, the LORD does not end there, but goes further to provide them with the vivid illustration of the eagle.
Those who put all their hope in God will “mount up with wings like eagles.” God has created eagles to be masters of flight. Although not the fastest of birds (flying from 20 to 75 mph, depending on their task at hand), eagles are known for their tremendous endurance. They can fly a great distance without resting because they make use of thermals (currents of warm air rising up) to conserve energy. While rarely flapping their wings, they can elevate in a thermal and glide down to catch the next thermal current. Thus, eagles can travel a great distance without becoming weary. This attribute of endurance is possibly illustrative of the statement “They shall run and not be weary, they shall walk and not faint.” But what does “mount up with wings” mean?
The Septuagint version (200 B.C.) translates verse 31 this way: “but they that wait on God shall renew their strength; they shall put forth new feathers like eagles.” Which is the identical meaning to “mount up with wings like eagles,” but a little more explanative. The text is describing the eagle’s molting process. Eagles will molt (their feathers fall out to make way for new growth) about once every year. This process is gradual, i.e. all the feathers don’t fall out at once but over a period of many months, giving the eagle the ability to continue in its ways like always. Thinking back to the text, this imagery of the eagle’s molt is demonstrative of the renewal of God’s people when they put their trust in Him. When the eagle gains its new feathers, the eagle looks fresh again, new again, young again. The psalmist makes this same point: “who satisfies your mouth with good things, so that your youth is renewed like the eagle’s” (103:5). They that wait upon the LORD shall be renewed to the point of youthful strength, nay better, for “even the youths shall faint and be weary, and the young men shall utterly fall, but those who wait on the LORD Shall renew their strength.” Even the youths grow tired and must stop their activities for the day, but the righteous will not grow tired trusting in God. Paul spoke on this same subject: “We are hard pressed on every side, yet not crushed; we are perplexed, but not in despair; persecuted, but not forsaken; struck down, but not destroyed” (2 Corinthians 4:8-9). How could these brethren continue on with strength through all of this peril? Because they have the “spirit of faith” (v. 13), “therefore,” he says in verse 16, “we do not lose heart. Even though our outward man is perishing, yet the inward man is being renewed day by day.” It is the inward man that is renewed like the eagle’s wings. It is the inward man, the soul, that is constantly renovated, becoming stronger in faith every day, and that stronger faith brings a sensation of freshness and youthfulness in our relationship with God. This is what God was telling His people, in Isaiah 40, who had lost faith. This is what we are reminded of today. “Therefore, my beloved brethren, be steadfast, immovable, always abounding in the work of the Lord, knowing that your labor is not in vain in the Lord” 1 Corinthians 15:58.