'Seven Spirits of God' in the Bible

To the angel of the Church at Sardis, write. These things says He who has the seven Spirits of God and the seven stars. I know your works, that you have the name of being alive, but are really dead.

From the throne issued lightning and voices and thunders. Seven blazing lamps were burning before the throne; these are the seven Spirits of God.

Then I beheld a Lamb standing as if slain in the midst of the throne and of the four Living Creatures, and in the midst of the Elders. He had seven horns and seven eyes (which are the seven Spirits of God, sent forth into all the earth).