'Seven Spirits of God' in the Bible

AND to the angel of the church in Sardis write, These things saith he that hath the seven spirits of God, and the seven stars; I know thy works, and that thou hast a name, as though thou wert alive, yet art dead.

And out of the throne issued forth lightnings, and thunder, and loud voices; and seven lamps of fire burned before the throne, which are the seven spirits of God.

And I beheld, and lo! in the midst of the throne, and of the four living beings, and in the midst of the presbyters, stood a lamb as just slaughtered, having seven horns and seven eyes, which are the seven spirits of God that are sent forth into all the world: