The Lord Almighty

"After this [the vision of the seven churches] I looked, and, behold, a door was opened in heaven: and the first voice which I heard was as it were of a trumpet talking with me; which said, Come up hither, and I will shew thee things which must be hereafter [that is, after the saints enter the open door and come up hither]." Revelation 4:1

The lesson of the open door indicates this "door" was not always open. Rather, it seems the "door in heaven" opens for the first time, and then the invitation is given to the John Class to enter through this "door" and to "Come up hither."
What a wonderful privilege is here extended to the saints. What an honor! It is not the great and mighty people of earth who are invited--only the John Class. Imagine the splendor as John ascends through this open door and sees the glorious vision of the throne scene reserved for those who love him.

The first voice mentioned in Revelation 4:1 refers most likely to Revelation 1:10 in which John says, "I was in the Spirit on the Lord’s day [the Sabbath day, the Millennial day], and I heard behind me a great voice, as of a trumpet [the King’s court majesty]." The same voice in Revelation 1:10 is engaged in Revelation 4:1, which shows us the throne scene of God. Appropriately, the majestic regal sound of a trumpet is employed to describe this vision.

"And immediately I was in the spirit, and, behold, a throne was set in heaven, and one sat on the throne." Revelation 4:2

John could not enter through this door in the flesh, but in the spirit-begotten condition, the John Class sees God’s throne and glory.
We see God’s glory in the Divine Plan of the Ages. Many in the churches today cannot see God’s glory. They see a throne in heaven, but on it they see a triune god, vindictively casting unsaved souls into a burning hell. Not much glory is there?

The One seated on the throne is none other than the Lord God Almighty. The throne represents God’s Divine government, which is in complete control of all things animate and inanimate, except for sinful mankind. Even here, in the outworking of God’s Plan, heaven and earth shall alike be under God’s control and dominion.

"Jasper" here probably represents a diamond. In Revelation 21:11 the jasper is said to be as clear as crystal. God is portrayed as translucent as a diamond. This seems to compare favorably with John’s description of Him, saying, "God is light, and in him is no darkness at all." 1 John 1:5
Paul supports the same thought in 1 Timothy 6:16, saying, God "dwells in unapproachable light." Because God’s true glory could not be seen by anyone in the flesh, John is shown the nearest thing to describe God’s glory and purity.

God is also described as being a "carnelian" stone, or a "sardine" or ruby--pure and translucent, but also red in hue. Red pictures love as shown in the ransom. Around God’s throne is a rainbow of emerald green representing God’s enduring or everlasting qualities.
The John class in the spirit-begotten condition is given a high and exalted view of God and His eternal government as seen from His glorious throne. This vision of God and His throne must never leave us. Only our knowledge of God’s plan through the ages, enables us to see God in such transcendent glory. It is a plan that promises "glory and honor for everyone that doeth righteousness."