But those who wait on the LORD shall renew their strength; they shall mount up with wings like eagles, they shall run and not be weary, they shall walk and not faint. – Isaiah 40:31
The children of God do find that, spiritually, their strength is renewed day by day. The outer man decayeth, that is nature: but the inward man is renewed day by day, that is grace. As thy days are, so shall thy strength continue to be. “Even the youths shall faint and be weary, and the young men shall utterly fail: but they that wait upon the Lord shall renew their strength.” Though days come one after another, so shall strength come with them; there shall be such a continuity of perpetual renewal that the heart shall be strong even to the end of life, and the old man shall know no inward decay.
An hour or so ago, I stood by what will certainly be the death-bed of one of our best friends, and I was cheered and comforted when I heard him so blessedly speaking both of the present with its pain, and of the future with its near descent into the vale of death. He said, “I have no doubt as to my eternal bliss. I have had no doubt-no, not a shadow of doubt-of my interest in Christ through my long illness. In fact, I have felt a perfect rest of mind about it all. And,” he added, “this is nothing more than ought to be, with us who listen to the glorious gospel, for we live on good spiritual meat. Sound doctrine should make us strong in the Lord. I have not been a hearer of yours for thirty years, and heard of covenant love and faithfulness, to die with a trembling hope. I know whom I have believed, and am persuaded that He is able to keep that which I have committed unto Him.” Thus, dear friends, shall we also be supported…Yes, as our days our strength shall be. – C.H. Spurgeon