In Revelation 4 we see the Lord God Almighty sitting on the throne of heaven, who is described as the Creator of all things:
Revelation 4:8 And the four beasts had each of them six wings about him; and they were full of eyes within: and they rest not day and night, saying, Holy, holy, holy, Lord God Almighty, which was, and is, and is to come.
9 And when those beasts give glory and honour and thanks to him that sat on the throne, who liveth for ever and ever, 10 The four and twenty elders fall down before him that sat on the throne, and worship him that liveth for ever and ever, and cast their crowns before the throne, saying,
11 Thou art worthy, O LORD, to receive glory and honour and power: for thou hast created all things, and for thy pleasure they are and were created.
In the next chapter, we read that the Lamb is in the midst of the throne with the elders.
The Lamb takes the scroll from the 1 who is sitting on the Throne being worshiped as the Creator of everything.
Revelation 5:6 And I beheld, and, lo, in the midst of the throne and of the four beasts, and in the midst of the elders, stood a Lamb as it had been slain, having seven horns and seven eyes, which are the seven Spirits of God sent forth into all the earth. 7 And he came and took the book out of the right hand of him that sat upon the throne.
Now in the Old Testament we frequently see YHWH described as the Creator of everything:
Isaiah 44:24 (NASB)
Thus says YHWH, your Redeemer, and the one who formed you from the womb, “I, YHWH, am the maker of all things, Stretching out the heavens by Myself and spreading out the earth all alone.
Isaiah 45:18 (NASB)
For thus says YHWH, who created the heaven (He is the God who formed the earth and made it, He established it and did not create it a waste place, but formed it to be inhabited), “I am YHWH, and there is none else.
Hebrews 1:10 quotes the psalmist:
“You, YHWH, in the beginning laid the foundation of the earth, And the heavens are the work of Your hands.."
YHWH is 1. ('echâd)
Putting all these verses together, one might conclude that it is YHWH who creates all things and sits on the throne, and the Lamb is someone else.
But is this what Trinitarians think?
According to Trinitarian interpretations of Revelation 4 & 5, who is being worshiped as the Lord God Almighty who created the heavens and earth? And who is this lamb who takes the scroll from the Creator's right hand?
For further clarity: "God is on the throne" does not answer the question. Which person/substance/essence/nature of the trinity concept is on the throne being worshipped as the 1 who created everything?
Scripture identifies "God Almighty" as YHWH. He declares this of Himself.
Genesis 17:1 Authorized (King James) Version
And when Abram was ninety years old and nine, YHWH appeared to Abram, and said unto him, I am the Almighty God; walk before me, and be thou perfect.
Exodus 6:3 Authorized (King James) Version
and I appeared unto Abraham, unto Isaac, and unto Jacob, by the name of God Almighty, but by my name YHWH was I not known to them.