So, brethren, here is the promise. God will give Himself to you, and in the very heart of your decaying nature will plant the seed of an immortal being which shall, like His own, shake off fatigue from the limbs, and never tend to dissolution or an end. The life of nature dies by living; the life of grace, which may belong to us all, lives by living, and lives evermore thereby. And so that life is continuous and progressive, with no tendency to decay, nor term to its being. 'The path of the just is as the shining light that shineth more and more,' until it riseth to the zenith of the noontide of the day. Each of you, looking forward to the certain ebbing away of creatural power, to the certain changes that will pass upon you, may say, 'I know that I shall have to leave behind me my present youthful strength, my unworn freshness, my buoyancy, my confidence, my wonder, my hope; but I shall carry my Christ; and in Him I shall possess the secret of an immortal youth.' The oldest angels are the youngest. The longer men live in fellowship with Christ, the stronger do they grow. And though our lives, whether we are Christians or no, are necessarily subject to the common laws of mortality, we may carry all that is worth preserving of the earliest stages into the latest; and when grey hairs are upon us, and we are living next door to our graves, we may still have the enthusiasm, the energy, and above all, the boundless hopefulness that made the gladness and the spring of our long-buried youth. 'They shall still bring forth fruit in old age.' 'The youths shall faint and be weary, but they that wait upon the Lord shall renew their strength.' There is one more point to touch, and then I have done, and that is the manner in which this immortal strength is exercised. The latter clauses of my text give us, so to speak, three forms of motion. 'They shall mount up with wings as eagles.' Some good commentators find in this a parallel to the words in the 103rd Psalm, 'My youth is renewed like the eagle's,' and propose to translate it in this fashion, 'They shall cast their plumage like the eagle.' But it seems much more in accordance with the context and the language to adopt substantially the reading of our English version here, or to make the slight change, 'They shall lift up their wings as the eagle,' implying, of course, the steady upward flight towards the light of heaven. So, then, there are three forms of unwearied strength lying ready for you, young men and women, to take for your very own if you like: strength to soar, strength to run, strength to walk.