He giveth power to the faint; and to [them that have] no might he increaseth strength. Even the youths shall faint and be weary, and the young men shall utterly fall: 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. (Isaiah 40:29-31)