When we left Genesis 25 last year, we'd been following the story of Abraham, who God had promised was going to be the one whose family line would bring blessing to the world.
In Genesis 25-50, we'll be following the "line of promise" - the family line which carries God's blessing. On the one hand, it was a promise that was going to be good for all the nations of the world. On the other hand, it was a promise that focused on just one thread of Abraham's family line. Like the right to the British throne, it was a birthright that would typically pass down through the oldest son. But also like the right to the British throne, reality can get a little messy.
Even in the worst of times and circumstances, God can somehow engineer good outcomes. It's just that we might not see it at the time!