'Seven Spirits of God' in the Bible

Then to the angel of the church at Sardis write thus: ??These are the words of him who holds the seven Spirits of God and the seven stars: I know your doings, you have the name of being alive, but you are dead.

From the throne issue flashes of lightning and loud blasts and peals of thunder. And in front of the throne seven torches of fire burn (they are the seven Spirits of God);

Then I noticed a Lamb standing in the midst of the throne and the four living Creatures and the Presbyters; it seemed to have been slain, but it had seven horns and seven eyes (they are the seven Spirits of God sent out into all the earth),