Scripture-first response
“God and the Lamb prove two divine persons.”
The Lamb represents the slain and risen human Messiah in God’s saving work. Revelation ends with one throne, servants who serve Him, one face, and one name.
What the objection is claiming
The sacrificial-symbolic distinction is treated as two separate Gods.
Revelation 22:1-4
1 And he shewed me a pure river of water of life, clear as crystal, proceeding out of the throne of God and of the Lamb. 2 In the midst of the street of it, and on either side of the river, was there the tree of life, which bare twelve manner of fruits, and yielded her fruit every month: and the leaves of the tree were for the healing of the nations. 3 And there shall be no more curse: but the throne of God and of the Lamb shall be in it; and his servants shall serve him: 4 And they shall see his face; and his name shall be in their foreheads.Open full referenceThe final vision presents one throne of God and the Lamb, servants who serve Him, one face, and one name.
How the passages answer it
Revelation distinguishes God’s invisible throne-glory from the Lamb as the visible, slain Messiah. Yet its final syntax deliberately converges: one throne of God and the Lamb, and singular pronouns for the One served and seen.