Fraz’s answer is quite good, I think: in point of fact, all sin and all die, yet all in Christ (who has died for all) are made alive.
In context of Ezekiel, though, the better question is: to what extent do the Prophets (including Ezekiel) teach that God seeks the restoration of those He has wholly ruined and sent to the pit?–keeping in mind that the notion of survival and restoration even of the righteous after death was pretty vague and spotty back then.
As to Roofus: how many times before the NT, or even during its narrative portions, has God tried to get His chosen representatives to pick up and run with some fairly simple notion–but they still only half-succeed or even utterly fail? (The excerpt today from Ez 18 being only one of very many examples that come to my mind.) UR looks as clear to me in the NT, and the OT, as trinitarian orthodoxy does: i.e., there are some tantalizingly obvious statements scattered here and there, as well as some apparently contravening testimony all over the place, but in the end it comes down to collating and slotting together very large amounts of evidence, nuance, implication and thematic linkages, as well as learning what kind of things to be looking and listening for. The methodology and careful study for arriving at both doctrinal sets, impresses me with their similarity.
Even so, I would say scriptural testimony is more ‘blatant’ about universalism more often, than about trinitarianism; probably because the former doctrinal set is simpler. But Jesus Himself, in the Synoptics, teaches in parables precisely so that His meaning will be obscured to those who harden their hearts in regard to justice: people who, at the time (and obviously for a long time thereafter) were willing to murder their own kinsman, whom they had been previously willing to accept as a teacher and a prophet in honor of themselves, once He challengedthem on the scope and character of God’s salvation.
Maybe it’s because I consider myself rather a Pharisee; or maybe it’s because I have a recognized tendency to enjoy being merely oppositional at times. But I had to come to terms with the fact that Jesus was mostly preaching against me, the “faithful” scholar. So, was I squinting my eyes and plugging my ears, and hardening my heart, so that I would not hear what God was saying?
The key turning point came when I sat down to parse out what it could mean, that if I did not forgive those who have sinned against me, God would not forgive me of my sins. Looking for limits to that, so that I could have a firm oppositional line where I could safely hate without having to forgive–I simply realized that I was trying to get around the injunction. It didn’t matter how far I extended it–even to Satan. If I was not willing to forgive Satan, then…
But if God was requiring me in principle to forgive and love and hope for the salvation of even Satan (whether or not I still had to oppose and fight him), then–how could it be that God would be less merciful than He was requring of me to be?
Also, at this time, I had just gotten finished working out my progressing synthetic metaphysic; which provided me with my first solid rationale, unexpectedly, for universal reconciliation–as a direct corollary of trinitarian theism. Plus, I think I had finally gotten around to reading George MacDonald’s Unspoken Sermons and The Hope of the Gospel. On top of which, I was in the throes of having to come to terms–which I very much did NOT WANT to do–with the evident fact that God was going to require me to sacrifice myself for the sake not only of someone I loved, but also for someone who from a purely natural standpoint I would be tempted to compete against in what amounted to impersonal hatred: nothing against him personally, just that he was in my way and… ARGH!! No, I was quite aware that that couldn’t be right; but neither did I want to endure the pain that God was pointing me toward. It took me another year or so for that to come to an almost-literal crux; but from the convergence of all these factors I was already philosophically speaking a quiet universalist. It took me a few more years before I had really studied the scriptures thoroughly enough to tell just how much of that sort of thing was in there or not.
So, no, it wasn’t easy for me, despite a sort of softness toward universalism in my heart from early times. What I came to realize, when I (self-critically) had to ask why I hadn’t been seeing this before, was that in my heart I was too selfishly hateful (even if not so much by other people’s standards) to have been able to hear it before.
The one that I love the most, sent by God Above, was instrumental (though she could hardly have realized this) in helping God to save me, and to save other people, from my sin. I didn’t learn universalism from her (although I know that she approves), and I certainly didn’t learn orthodoxy from her (of which she has no particular concern); but I learned true love from being given to her–both as a gift from God and as a crucifixion of my self that I had to willingly undergo, or else be found to be striving against the One Who loves her most.
And that had to have made more difference than anything.
(Anyone willing to pray for me, is certainly welcome. God knows I need it. I hope that God will be finished with killing me someday… For once I have finished dying, then I can live. But dying to my self is very very very very hard.)
(Also, as I try to warn anyone thinking of becoming a Christian: count the cost. There’s a pretty good chance that God will require you to be scourged and crucified. )