"And I beheld, and, see, in the middle of the throne and of the four beasts, and in the middle of the elders, stood a Lamb as it had been slain, having seven horns and seven eyes, which are the seven Spirits of God sent forth into all the earth.

And he came and took the book out of the right hand of him that sat on the throne. And when he had taken the book, the four beasts and four and twenty elders fell down before the Lamb, having every one of them harps, and golden vials full of odors, which are the prayers of saints.

And they sung a new song, saying, You are worthy to take the book, and to open the seals thereof: for you were slain, and have redeemed us to God by your blood out of every kindred, and tongue, and people, and nation; and have made us to our God kings and priests: and we shall reign on the earth."

Revelation 5:6-10

To whom is the writer referring in this passage? Who will reign on the earth and when exactly will this take place?