What are the three heavens? What are the seven spirits of God?

The Bible speaks of three heavens: The first is the sky—earth’s atmosphere. The second is the stars—what we refer to as “space.” The third is where God rules, where according to the Bible He sits on His throne. As David celebrated: The Lord is in his holy temple; the Lord is on his heavenly throne—David, Psalm 11:4a. But of course God is not a being limited by space or time. Rather, He is infinite and everywhere all at once. As Solomon so correctly observed, The heavens, even the highest heaven, cannot contain you—Solomon, I Kings 8:27a. This third heaven is also where Jesus sits, at the right hand of the Majesty in heaven—Hebrews 1:3b.
The seven spirits of God are referenced at the beginning of the apostle John’s book of Revelation: 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. There are two thoughts that are commonly held by scholars regarding the reference to the “seven spirits”: (1) that it is a reference to the Old Testament prophet Isaiah: A shoot will come up from the stump of Jesse; from his roots a Branch will bear fruit. The Spirit of the Lord will rest on him—the Spirit of wisdom and of understanding, the Spirit of counsel and of power, the Spirit of knowledge and of the fear of the Lord—and he will delight in the fear of the Lord. He will not judge by what he sees with his eyes, or decide by what he hears with his ears—Isaiah 11:1-3; and (2) that it represents God’s Holy Spirit, with the number “7” representing perfection or completeness, thereby conveying the complete perfection and fullness of the Holy Spirit.