The reading on which the sermon is based is Revelation 5: 1-10.
A passage full of rich imagery especially of Jesus who is described as a lion and seen as a lamb which could lead to confusion but actually leads to revelation and frees us to sing a new song.
In your own reading of the passage you might want to consider:
Why is Christ the only one worthy enough to open the scroll?
What does it mean that he is both a lion and a lamb?
What does this mean to you?