Like the Israelites, when they were surrounded by the Assyrians, we get surrounded by what we can't control. In other words, at times when we know we're in trouble, we know we're not getting out of this. But when you take God seriously, have faith in Him, and stay close to Him, things will happen. Isaiah assures King Hezekiah of the Lord's protection if he trusts him. Hezekiah decides to do so, and an angel wipes out 185,000 Assyrian soldiers via a "mysterious plague". God will demonstrate His power and give strength to the weary when one places their faith in Him, cause that's what He's looking for.