Passing through very briefly (well, very briefly by my standards… 
) : but I understand the distinction being one of cooperation or else a continued insistence on not cooperating. (Calv and Arm soteriologies typically come down to the same thing, in different ways–a continued insistence on not cooperating with God.)
Our God is a consuming fire, and the Holy Spirit is the only fire that can rightly be called unquenchable. As that pop-cultural Christian youth charismatic and evangelical show likes to put it, we’re supposed to be acquiring the fire. Are we working with the fire or against it?
If against the fire, then the fire will be wrath against us as well as against our sins (as even Calvs and Arms agree in various ways). If with the fire, then the fire will only be against our sins. It’s another way of talking about our relationship to the Holy Spirit.
Put briefly, those who continue to fondle their sins (as the Greek puts it) in RevJohn, are still acting against the fire. The Bride/Church exhorting them to slake their thirst and wash their robes etc., are cooperating with the fire: the Holy Spirit, Who is the unquenchable fire, is saying “Come!” In one sense the Bride could be said to be outside the lake of fire (maybe standing on top of it, as earlier imagery in RevJohn puts it, practically though not explicitly saying they have come out of the lake of fire); but in another sense the Church of the Bride is in the Fire and the Fire is in them, vastly moreso than the ones who are still fondling their sins.
That won’t be a crisis for us; it will be a crisis for them.
(But, Jesus’ notion of who exactly counts as “us” and “them” may be very surprising and even shocking. His notion is also the only notion that ultimately counts. 
I accept this to mean that I had better be prepared to find Him accepting everyone else except me, the chief of sinners. The safest thing seems to be to rejoice in the judgments of God against myself. He who tries to save his soul, yet he who loses/destroys his soul for the sake of Christ and for His name and for the gospel, etc.)
In my third novel (not yet published, so I’ll try not to be too spoilish about the plot), I try to illustrate what I’m talking about in an important scene about 2/3 through the book: a righteous man grieving against his own sins, such as they are, wishes death for himself, and God grants his wish. The man wakes from the destruction he had prayed against himself, lying in a bright fog on snow apparently made of light–he could feel the light growing around him as he is praying, and in his grief against his sins he had prayed for it to burn him to ash. He soon realizes that the fog and the feathery snow are actually the fire of God (although he doesn’t recognize the fire as being the Holy Spirit, not having our categories of thought on the topic.)
The guardian angel of his people, whom he (and his people) had feared had abandoned them, has wakened him to have a talk with him, to reassure him about several things–but also to test just how far this man is willing to accept the judgment of God against his sins. Because he hadn’t yet really faced the depth of his sin; he had made a start of it, but he was still avoiding facing up to some of it.
When the angel challenges him with the full extent of his crime, the man has a choice about where he would prefer the fire of wrath to fall–one choice of which is that it should fall on the angel for telling him a truth he would rather not have heard! Instead, although tempted to do otherwise, he calls the wrath of God against that sin upon himself. Consequently, the Spirit is not fire to him but light; and he is sent back to life with a commission from God to get off his butt and start taking responsibility for living and dying to find and give hope to other people, rather than daffing his responsibility so that other people will take that risk in his place. (Soon afterward he leads a brother of his to repentance and the acceptance of God’s salvation, when his brother could only see condemnation for himself.)
Persistently impenitent sinners in the story, though, once their bodies have died, perceive the Holy Spirit as an ocean of fire burning them–an ocean either firey black (representing the squinting shut of their own spiritual eyes against the light), or blindingly bright (with truth that they are sort-of trying to see but still want to twist to their own supreme advantage.)
In all this I am trying to illustrate a notion common (though not universal, insert irony here ) among Calvs, Arms and Kaths alike, about our relationship to God affecting how we perceive the action of God toward us, especially the action of the Holy Spirit. But while our subjective perceptions of God’s action may vary, the action itself objectively remains the same: for God is love, and does not have two minds about us.
I could tell that the writers of the stage drama that progressed over the weekend had at least CS Lewis in mind; maybe Lewis’ teacher MacDonald, too.)