It makes sense the throne would have captured John’s attention first. It was at the center of his vision, glorious, radiating a cascade of rainbow light. That he noticed the elders next also makes sense, as they were human in appearance.
The four living beasts were also at the center of the scene, and their unique appearance must have taken time to take in. As John watched, a paean of praise broke forth, the elders threw themselves prostrate before the throne, casting their crowns into the glistening pool of light all around the throne.
It was only then John saw a scroll placed beside the One sitting upon the throne.
The Scroll
Then I saw upon the right hand of the One sitting upon the throne a scroll having been written within and on the back, having been securely sealed with seven seals.
And I saw a powerful angel proclaiming in a mighty voice, “Who is worthy to open the scroll and loosen its seals?”
And no one was able—in heaven, nor upon the earth, nor under the earth, top open the scroll nor to behold it.
Then I myself was greatly lamenting with a loud cry of pain for not even one was discovered worthy to open the scroll nor to behold it.
Revelation 5:4

Why was John so moved?
Historicist
Matthew Henry, a well-known commentator from the late seventeenth, early eighteenth century, took the historicist’s point of view, and considered the scroll to contain God’s purposes and plans concerning the church and the world. These are the future things already ordained by God.
It seems as soon as he saw the scroll, John intuitively understood its significance and importance.
He wept because he so longed to know what the future would hold. Life was precarious for first century Christians, persecution fierce, faith a costly and risky venture. Within that seven-sealed scroll were the answers, the persevering hope and courage to endure they so desperately needed.
But now, seemingly, it would never be opened.
The stage was set for Jesus to enter, as only one person—a person so unique there is and never has been anyone like him—may open this scroll, because only one person may disclose to humankind the future God has written.

Preterist
In an entirely different perspective, the scroll held the sentence handed down by the Judge of the Universe against Jerusalem for the part it played in the severe oppression, ill-treatment, and killing of Christians. This is the final act begun with Jesus’s indictment through His seven woes (perhaps the seven seals are correlated, here).
“Jerusalem, Jerusalem, the city that kills the prophets and stones those who are sent to it! How often have I desired to gather your children together as a hen gathers her brood under her wings, and you were not willing!
See, your house is left to you, desolate. For I tell you, you will not see me again until you say, ‘Blessed is the one who comes in the name of the Lord.’”
Matthew 23:37-39 (NRSV)
It was not long before the scribes and Pharisees did indeed bring about the very terror Jesus decried.
… when they had called in the apostles, they had them flogged. Then they ordered them not to speak in the name of Jesus and let them go.
As they left the council, they rejoiced that they were considered worthy to suffer dishonor for the sake of the name.
… they dragged him out of the city and began to stone him, and the witnesses laid their coats at the feet of a young man named Saul. While they were stoning Stephen, he prayed, “Lord Jesus, receive my spirit.”
And Saul approved of their killing him.
That day a severe persecution began against the church in Jerusalem, and all except the apostles were scattered throughout the countryside of Judea and Samaria.
Acts 5:40-41, 7:58-8:1 (NRSV)
From this perspective, John was ushered into the courtroom just as the judgment was about to be handed down, but no one was found worthy to execute justice. For John and the apostles, who had witnessed the first martyrs, and experienced the onset of the Sanhedrin’s program of persecution, this would be bitter discouragement to leave the deaths of Christians without vindication.
Alternatively, the scroll represents the New Covenant, and only One may mediate it. This is in itself a a kind of judgment, as the writer of Hebrews expressed,
In speaking of a new covenant, he has made the first one obsolete, and what is obsolete and growing old will soon disappear.
Hebrews 8:13 (NRSV)

Futurist
The Dispensionalist point of view sees the scroll as the title deed to the earth. Evidently, Roman law required wills to be sealed seven times. Therefore, the scroll represented God’s will, that only One could inherit.
The fearsome judgments that occur at the breaking of each seal represent God reclaiming earth. Originally, the Lord created the earth for humankind, then deeded this planet to humanity with God’s blessing, saying,
“Be fruitful and multiply and fill the earth and subdue it and have dominion over the fish of the sea and over the birds of the air and over every living thing that moves upon the earth.”
Genesis 1:28 (NRSV)
But humankind lost dominion of the world, forfeiting it instead to Satan, in a moment of tragic deception and rejection of God’s authority.
This is why Satan could tempt Jesus in the way he did.
Again, the devil took him to a very high mountain and showed him all the kingdoms of the world and their glory, and he said to him, “All these I will give you, if you will fall down and worship me.” Then Jesus said to him, “Away with you, Satan! for it is written,
‘Worship the Lord your God,
Matthew 4:8-10 (NRSV)
and serve only him.’”
Now, God would redeem what was lost, restore what had become corrupted, resurrect what had been put under the dominion of death. But along with that redemption would come judgment.
All this is in keeping with ancient Jewish law that provided for a kinsman redeemer to restore a lost inheritance.
If anyone of your kin falls into difficulty and sells a piece of property, then the next of kin shall come and redeem what the relative has sold
Leviticus 25:25 (NRSV)
The kinsman had to be related—be kin—and also had to have ready the entire purchase price, something only Jesus could do from humanity, being fully human (kin) yet also fully God (infinite and eternal).
You know that you were ransomed from the futile conduct inherited from your ancestors, not with perishable things like silver or gold but with the precious blood of Christ, like that of a lamb without defect or blemish.
He was destined before the foundation of the world but was revealed at the end of the ages for your sake.
1 Peter 1:18-20 (NRSV)

Spiritual
This position considers the scroll as God’s redemptive plan.
- It is in the right hand of God, symbolizing God’s power and authority.
- Every available space on the scroll, both the inside and the outside, has been written upon, so nothing can be added to God’s plan.
- It is sealed, so nothing may be subtracted from it, either.
- The mighty aspect of the angel, with both a tremendous voice and a forcible character, is necessary so the entire cosmos may be alerted to this challenge—not just the heavens and the earth, but also that mysterious realm under the earth.
- The call is for one who is worthy to bring about God’s redemption.
John weeps because God’s restoration of the world, of all that is, must seemingly now be delayed.

The four perspectives taken from Revelation: Four Views A Parallel Commentary, edited by Steve Gregg