‘And when the living creatures will give glory and honour and thanks to him who sits on the throne, to him who lives for ever and ever (unto the ages of the ages), the four and twenty elders will fall down before him who sits on the throne and will worship him who lives for ever and ever, and will cast their crowns before the throne, saying, “Worthy are you, our Lord and our God, to receive the honour and the glory and the power, for you created all things, and because of your will they came into existence (‘they were') and were created”.'
The living creatures, as the close servants of God, lead the praise. They continually give glory and honour and thanks to Him Who is seated on the throne, the One Who created all things, the One Who reigns. (The ‘continually' comes from the use of the future tense, which here means ‘whenever they do it then ----', the writer's way of rendering the Hebrew ‘imperfect').
Then the elders make their reply. They, of course, are aware that the living creatures represent the whole of creation, and they cast their crowns before God and speak of God's whole creation. All things came into existence through His will, He created them in accordance with His will. Thus is He worthy to receive the worship of all creation through the living creatures. It is the fact that He is the Lord of Creation that gives Him the right to do what is about to be done, the releasing of creation from its dreadful bondage (Romans 8:19-25). It came into being by His will, and it is His. Now He will restore it fully. (The song is fourfold as befits a song celebrating creation, compare Revelation 5:13).
Notice the stress on the fact that He is the One Who lives for ever and ever and that He is the One Who sits on the throne. From everlasting to everlasting He is God. As the living creatures had earlier said, He is the One Who was and Who is and Who is to come, the Almighty God. He is the One Who created all things, He is the One Who is sovereign over all things, He is the One Who will bring all things into subjection to Himself, and in recognition of this the elders fling their crowns at His feet in submission and worship Him, on behalf of His people whom they represent. This leads on to the next action.