I was watching an eagle in flight when for no apparent reason it began spiraling upward. With its powerful wings, the great bird soared ever higher, dissolved into a tiny dot, and then disappeared.

Its flight reminded me of Isaiah's uplifting words: "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; they shall mount up with wings like eagles" (40:30-31).

Life's heartbreaks and tragedies can put an end to our resilience, our endurance, our nerve, and bring us to our knees. But if we put our hope in the Lord and rely on Him, He renews our strength. The key to our endurance lies in the exchange of our limited resources for God's limitless strength. And it is ours for the asking.

With God's strength we can "run and not be weary," even when days become hectic and demanding. With His strength we can "walk and not faint," even though tedious, dull routine makes the way seem dreary and long. The psalmist exclaimed in the midst of his weary, tearful pilgrimage, "Blessed is the man whose strength is in You" (Psalm 84:5).

Oh, what an exchange—God's infinite strength for our finite weakness!  — David H. Roper