After hearing brief messages from Jesus, John is invited through a doorway into the heavenly realm, where a voice promises to show him "what must take place after this."
John sees strange visions of a throne surrounded by thunder, and twenty-four elders (twice the symbolic number twelve, the number of the tribes of Israel and later Jesus' apostles) with four living creatures (echoing Ezekiel ch. 1, and later taken as symbolizing the Four Gospels--Matthew, Mark, Luke and John).
As other-worldly as this scene is, the setting is somewhat familiar: all these elders and creatures are at worship. Another interesting detail is that as soon as John enters the heavenly door, the narrative shifts from past tense to present tense. The heavenly hosts sing "Day and night without ceasing," and their song would be familiar to students of the prophet Isaiah (See Is. 6:1-8), or been present at a Christian Communion service.
"Holy, Holy, Holy, is the Lord God Almighty,
who was and is and is to come."
Though many readers of Revelation focus on its messages for "our future," what I take from this eternal worship song in present-tense, is that what we call "heaven" is a space of God-consciousness that exists outside of linear time. Anytime we, as human beings, regardless of language or time period or form of music, tune into this "frequency", so to speak, we are communing with eternity. We are stepping out of the illusion of the causal "first this, then that" of earthly time, into the ongoing "NOW" of God's holiness. It's only by God's grace that John, or we, or any earthly creature can tune into this reality. Yet in Christ, the door is always open. At the communion table, and even in our homes, in times of prayer and reflection. I'm still awestruck every time.
4. I looked, and there stood open heaven’s door!
I, by a trumpet’s voice, was welcomed through.
One Lord, like precious stones, with twenty-four,
The elders, in white clothing, give their due
As do four living creatures, full of eyes,
A lion, ox, a human, and an eagle
With six great wings, as chanting voices rise
Both day and night, before the throne so regal.
“Kadosh, Kadosh, El Adonai, whose reign
Both was and is, and shall be evermore!”
So vast the sea of glass, with thund’rous flame
Creation stands and worships on the shore
Now join we singing with eternity
In reverence and awe, to be set free.