"Then He who sat on the throne said, 'Behold, I make all things new" (Revelation 21:5). We saw the throne of God in Revelation 4:2-4. There was a rainbow around the throne, as a sign of God's mercy. Never again would He destroy the earth with a flood. Again, we saw the throne of God in Revelation 20:11-12. It is the great white throne of judgment. Now, we see the throne of God in Revelation 21. No emphasis is on its appearance. The focus is upon God's voice.
The throne of heaven is a symbol of God's sovereign dominion over all. When He speaks, it shall be done. He decrees what shall come to pass. His word is with absolute sovereign authority. God said to John, "Write, for these words are true and faithful" (Revelation 21:5). God cannot lie (Titus 1:2). He is the God of all truth. He is faithful to His word to perform it.
From the throne of heaven, God's voice declared our salvation. God said, "He who overcomes shall inherit all things, and I will be his God and he shall be my son" (Revelation 21:7). And, how do we overcome? The Bible is clear. "Who is he who overcomes the world, but he who believes that Jesus is the Son of God?" (1 John 5:5). Salvation is believing on the Lord Jesus Christ (Acts 16:30-31).
From the throne of heaven, God's voice declared judgment and condemnation for all who are unbelieving (Revelation 21:8). They shall experience the second death in the lake of fire. The word death (Grk: thanatos) does not mean annihilation but separation. That is separation from God forever in the lake of fire. "He who believes in the Son has everlasting life; and he who does not believe the Son shall not see life, but the wrath of God abides on him" (John 3:36).
