Isaiah 40 : 28-31
The LORD is the everlasting God , the Creator of the ends of the earth . He will not grow tired or weary , and his understanding no one can fathom . He gives strength to the weary and increases the power of the weak . Even youths grow tired and weary , and young men stumble and fall ; but those who hope in the LORD will renew their strength .
They will soar on wings like eagles ; they will run and not grow weary , they will walk and not be faint .