"John to the Seven Churches which are in Asia; Grace be unto you, and Peace, from Him which Is, which Was, and Which Is to Come: And from the Seven Spirits which are before His Throne" (Rev.1:4).

First off, why seven?

The number "Seven" in the Book of Revelation is very significant.
There are Seven Churches, Seven Letters, Seven Stars, Seven Candlesticks, Seven Spirits of God, Seven Lamps of Fire, Seven Seals, Seven Trumpets, Seven Horns, Seven Eyes, Seven Thunders, Seven Heads, Seven Crowns, Seven Angels, Seven Vials, Seven Mountains, etc.. The number "Seven is found throughout the Scriptures denotes completeness, universality, and perfection.
Now all of these, each one has a meaning within themselves, and are found within the Pages of this Great (Letter) Book. It would be good of you to read this day.

:HOLY SPIRIT:

The phrase, "And from the Seven Spirits which are before His Throne," is given to us
in this manner, in order to emphasize the Sevenfold aspect of His (the Holy Spirit's)
operations. Whose Gifts are given among the Churches, and Who divides to every man as He will.
The Sevenfold aspect of the Holy Spirit speaks of totality, completion, and perfection.
But yet, the number "Seven" carries with it a literal application.
Isaiah tells us what it is (Isa.11:2).

1). The Spirit of the Lord.
2). The Spirit of Wisdom.
3). The Spirit of Understanding.
4). The Spirit of Counsel.
5). The Spirit of Might.
6). The Spirit of Knowledge.
7). The Spirit of the Fear of the Lord.

If it is to be noted, the Holy Spirit is pictured here "before the Throne"
This refers to the fact that the Holy Spirit works primarily on Earth. In fact, all that the Godhead does for the human race is done strictly through the Person and Office of the Holy Spirit.
And as you read, you shall see in Revelation 5:6, His Work is all within the Parameters of the Finished Work of Christ, i.e., "what He did at the Cross"

Come Holy Spirit, move over me.
By Your Anointing, set me free.
Pour out New Wine, on this thirsty hear of mine.
Come Holy Spirit, move on me.