Who are the seven spirits?

John, To the seven churches in the province of Asia: Grace and peace to you from him who is, and who was, and who is to come, and from the seven spirits before his throne.  Revelation 1:4

The message is sent to the seven churches in Asia (Turkey).  They followed, in order, according to a known Roman postal route.

The mystery of the seven stars that you saw in my right hand and of the seven golden lampstands is this: The seven stars are the angels of the seven churches, and the seven lampstands are the seven churches.  Revelation 1:20

From the throne came flashes of lightning, rumblings and peals of thunder. Before the throne, seven lamps were blazing. These are the seven spirits of God.  Revelation 4:5

Then I saw a Lamb, looking as if it had been slain, standing in the center of the throne, encircled by the four living creatures and the elders. He had seven horns and seven eyes, which are the seven spirits of God sent out into all the earth.  Revelation 5:6

All of these things appear to refer to the same thing:  Seven spirits are the seven lamps (4:5).  The seven lamps are the seven churches. (1:20)

Seven spirits = Seven lampstands = Seven churches

Does it mean Seven literally churches only?  The number 7 means perfection, a fulfillment so it could mean ALL churches.