I would like to present what I just learned about Isaiah 40:31. "But those that wait on the Lord shall renew their strength; they shall mount up on wings like eagles, they shall run and not grow weary, they shall walk and not faint." (NKJV) This waiting is a waiting for...waiting for the Lord to move, thus resting in Him. This resting in Him renews our strength..."Come to Me, all you who labor and are heavy laden, and I will give you rest. Take My yoke upon you and learn from Me, for I am gentle and lowly in heart, and you will find rest for your souls. For My yoke is easy and My burden light." Matthew 11:28-30. They shall mount up on wings like eagles...how does an eagle mount up? An eagle mounts up in two ways: either using an updraft or a thermal(both are rising air). The eagle moves into this rising air, spreads it's wings and it lifts up, allowing it to take off flying with very little effort. Eagles do most of their flying by soaring or gliding which relies on air to lift them up and provide most of the power when flying. There is a powerful picture painted here for us: just as the eagle is lifted up by the air and uses the air to power it's flight, so are we lifted up and empowered by the Holy Spirit. All we need to do is wait on the Lord, open our wings(submit) and He will carry us to where we need to go, with little effort on our part....our yoke is easy, our burden is light. We run and don't grow weary and walk and not faint because it is the Lord that does the work in us. He does the hard work. I hope this blessed someone. I tried to write it out the way I understood it.