I share your appreciation for Genesis 50:20: "As for you, you meant evil against me; but God meant it for good, to bring it about that many people should be kept alive, as they are today" (RSV). It’s one of my favorite Bible verses too.
Jacob and all his sons are living in Egypt under the protection of Joseph. When Jacob dies, the brothers who had conspired to sell Joseph into slavery were afraid that without the father’s calming influence, Joseph might take his revenge. They go to seek his forgiveness.
But Joseph has grown in spiritual awareness through all the many challenges of his life. He is able to look back over experiences of slavery and imprisonment, followed by elevation to the highest ranks in Egypt and responsibility for the welfare of many, and sees through it all a divine design. It is so for us as well. We may live lives of mistakes, challenges, coincidences that seem random and haphazard as we go through them. But occasionally we can pause, look back and have a "Joseph moment" when we can see the guidance and energy of God at work through it all. Others may have meant evil against us—we may have meant evil ourselves. But the potential for good was always there, in the Omnipresence of God. It’s humbling, astonishing and very reassuring.