Worthy is the Lamb (Revelation 5:1-10)

The scene that unfolds across the 4 chapters of Revelation 4-7 is a vivid retelling of the history of the world from the perspective of the throne room of God. And in the center of this scene is the Lamb who is worthy to break the seals of the scroll that tells the story. So what makes Him worthy? And why is the cross the lens through which we are to view the events of the world?