[This is a [b]reaaaaaally long post. Read at your own peril. But I think I do fairly accurately describe the gist of McClymond’s view and offers some at least plausible objections.]
I just finished watching the lecture. I figured I’d give a brief summary. Basically, McClymond is doing a genealogy in which he attempts to show that universalism is rooted in the supposed gnostic narrative of “unity --> diversity --> unity.” He blames Origen for picking this up. Then, he skips to the 16th and 17th century mystic Jocob Boehme, blames him for creating an esoteric, gnostic-influenced version of apokatastasis and tries to show how all the universalists in the modern period can be traced back to Boehme.
McClymond anticipates the charge that he is using a sort of “guilt-by-association” tactic, but he denies this on the grounds that it is not only that universalism is associated with gnosticism, but that it “comes directly out of a gnostic conception of God.” What this gnostic doctrine of God exactly is is not entirely clear, but it appears to include: (a) emanationism (God does not freely create the world), (b) evil is somehow originally present in God, leading to the emanation of fallen material creation, and © that all is brought back into unity with God in such a way to deny a real distinction between God and creation. He asserts that universalism is simply not biblical and thus false, saying: “Even if the New Testament did not clearly deny universalism, we could still reject it because of its gnostic foundations.” The only biblical argument he uses to support his claim that scripture teaches a doctrine of everlasting hell is the crucifixion narrative of the two thieves, one who accepts and the other who rejects Christ.
He goes on to assert that universalism has no essential place for sin or grace. This really begins the section of his lecture which, I think, contains some just flat-out embarrassing statements. Some choice ones:
“Is it not noteworthy that the [supposed] “truth” of universalism should be discovered at a period of time in church’s history that is recognized as a period of moral laxity and cheap grace?”
“I see universalism at the 21st century as just a new expression of the age old struggle between cheap and costly grace.”
“I call us all to recover the central message of the cross…because it’s only a Church that has forgotten the message of the cross that could even toy with the idea of universal salvation as biblical truth.”
Alright, now that summary is out of the way, time for some critiques! 
First of all, I should say that my training is not primarily in historical theology, but rather philosophical theology and philosophy of religion. However, I have taken enough courses in historical theology to have a basic feel about what’s going on in the field. That being said, the very fact that McClymond would base his entire thesis on the idea that universalism is an essentially gnostic invention is puzzling, since the consensus in the field seems to be that there never was some single phenomenon of “gnosticism.” We do not have primary sources of the gnostics that McClymond cites, but rather only the polemical documents of “proto-orthodox” theologians. If I am correct, we have only relatively recently come upon the first primary documents from supposed “gnostics” such as Valentinus, and in many ways they do not match up with the views that polemical proto-orthodox theologians such as Irenaeus ascribed to them. So, that alone seems to be a prima facie methodological problem for McClymond’s narrative: how can we genealogically trace universalism to gnosticism when we’re not even sure what the supposed “gnostics” believed? This does not, I think, completely nullify his narrative. For example, it seems the general gist of his genealogy could remain intact if the formulation of these “gnostic” universalist views found in the proto-orthodox fathers was enough to spawn this universalist trajectory. Still, as I will argue, I don’t think that the most important theologians that McClymond cites do hold these “gnostic views.” That is the bigger problem with his account.
Secondly, McClymond seems to be simply picking up on the old and insufficiently critical notion that Origen was just another gnostic who hid it better than others. But, remember, Origen himself vigorously debated against the “gnostics” of his time. McClymond’s case depends not only on the weak claim that universalism shares some approximate similarities with “gnosticism” but the stronger one that it “shares a gnostic conception of God.” McClymond has to explain how Origen’s doctrine of God is really “gnostic” when Origen was explicitly developing his doctrine of God in opposition to these supposed gnostics! I have not read all that much of Origen besides De Principiis and some bits of Contra Celsum, but I have to say that I do not recognize McClymond’s conception of gnosticism (unity-division-unity) in Origen’s thought. Even if we accept that Origen believed in the pre-existence of souls who sinned against God, were placed in material creation, and are reconciled back to God, this does not entail that Origen held to a form of emanationism that denies God’s free act of creation, that the material world is inherently sinful, that there ever was “sin” in God, or that finally any distinction between God and creatues is erased. Despite perhaps some oddities in his doctrine of the Trinity, Origen’s doctrine of God and narrative of creation are pretty similar in their basic structure to the more traditional views; it’s just that he pushes the Fall up an ontological level, so to speak. Perhaps I’m mis-reading Origen or I’m just so thick-headed as not to see Origen’s gnosticism.
Thirdly, and this is a relatively minor point, McClymond frankly just engages in a bunch of cheap shots. Since an essential part of his narrative is that universalism is inextricably linked to “esoterica” and “visionaries,” he typically mentions a supposedly bizarre position held by each universalist (e.g. that Lucifer might be saved, God forbid! or Adrienne von Speyr’s claim that she mystically “went to hell” every Holy Saturday), many times for no discernable reason other than to make the thinker in question seem silly. The height of this absurdity occurs when he invokes some charismatic preacher named John Crowder who apparently holds rowdy services and performs odd acts like pretending a crucifix is a bong. Perhaps Crowder has a larger following than I am aware of, but I doubt it, and I think that McClymond’s inclusion of him in this narrative serves no other purpose than to implicate the actual respectable thinkers by their supposed association with Crowder’s bizarre heterodoxy.
Moreover, it is unusual that MyClymond chooses, until the 20th century, to skip over the more well-reputed likely supporters of universal reconciliation. He says nothing directly, for example, of Gregory of Nyssa (or the other Cappadocians, who some seem to think have universalist leanings), who only helped formulate the doctrine of the Trinity! Additionally, if McClymond relies so heavily upon universalism belonging to the realm of “visionaries,” why not mention Julian of Norwich in his narrative? Perhaps he doubts her universalist leanings, but it seems to be that he ignores her simply because she is theologically “respectable” in a way that Boehme, for example, is not (at least among the more theologically traditional).
Of course, McClymond’s narrative only works if all and every form of Christian universalism necessarily shares the same “gnostic” conception of the doctrine of God. Again, I think I have called into question whether this can even be said of Origen, who typically has been interpreted as being pretty close to gnosticism. I have no doubt that Boehme held some heterodox views and that these were picked up by Hegel and thus influenced a great deal of 20th century theologians. However, to suggest that all these theologians simply picked up wholesale this supposed gnostic doctrine of God (which we don’t know was actually held by any “gnostics”) and that it is the foundation of their universalism just seems flat-out implausible. Does McClymond really want to suggest that von Balthasar holds a gnostic conception of God? He, like Origen, actively fought against this, and Cyril O’Regan - the leading scholar of the “gnostic influence” in modern thought - claims that von Balthasar is one of the strongest anti-Hegelian (and thus, on McClymond’s narrative, anti-Boehmian --> anti-gnostic) modern theologians.
McClymond, I think, is appealing to the similarity in the supposed gnostic narrative of “unity-diversity-unity” and the traditional narrative of “creation-fall-redemption” and then only selectively identifying universalist Christian theologians’ with the former. But none (as far as I am aware) of the major theologians he cites believe in an emanationist doctrine of creation, of some primordial “sinfulness” in God, or any of the other supposed doctrines that he describes as gnostic. The only distinctions left between them and those good, old traditional theologians are their universalism and the fact that other areas of their theologies consequently look different (atonement, God’s justice/wrath, etc)!
Finally, let’s consider McClymond’s more explicit critiques of universalism. First of all, it’s just silly to assume that an increase in the popularity of universalism in the 20th and 21st centuries is due to the “moral laxity” of the modern age and the “cheap grace” of the (liberal) modern church. It seems to me there is a whole cornucopia of other factors that likely play far greater a role in this shift: watching those who aren’t “saved” die by the millions in the Holocaust and other atrocities of the 20th century, changes in biblical scholarship that open up new ways of reading the gospels and Paul, the re-evaluation of Origen as not a “gnostic,” etc. etc. “Liberalism” and “moral laxity” might have affected some to accept universalism, but to suggest that these are the only causes is just ridiculous.
Additionally, McClymond cannot charge his characterization of universalism with holding to “cheap grace” unless he is already assuming a certain conception of grace that inherently holds to a hell of eternal conscious torment. But this is precisely what is in question! How can one read Robin Parry, as McClymond has claimed he has, and say that Parry advocates cheap grace, rejects the wrath or justice of God, or has no place for evangelism unless one has already a priori ruled out the possibility? McClymond’s definition of true “grace” and “justice” requires that one already hold to a doctrine of God’s wrath/justice in which God punishes those who do not receive grace with eternal suffering in hell. But this just means that McClymond has already smuggled the doctrine of everlasting hell into his doctrine of God and God’s attributes. The universalist need not (and almost never does) deny that God does not display God’s wrath or justice; it’s just that this justice is always working for reconciliation and never for pure retribution.
In fairness, McClymond does attempt to support this assumption by an appeal to the biblical narrative. Here, as I mentioned, he puts forth, as far as I can remember, only one real argument for his view that God’s justice/wrath requires that human beings make a choice of eternal consequence: the two thieves. McClymond uses the example of the thief who mocks Christ as an example of the one who rejects grace and thus deserves eternal punishment, whereas the thief that accepts Christ gains grace and earns everlasting bliss. But, just moments later, McClymond himself mentions how the “good” thief extraordinarily accepts Christ while Christ’s own apostles are denying him and scattering! But this means they did nothing different from what the “bad” thief did! The only difference is that the bad thief dies without repenting, whereas the apostles have the further opportunity to repent. But this leaves a few issues unresolved. As I think McClymond would admit, this story alone does not support his doctrine of hell; it can only do so in conjunction with his interpretation of other passages as pointing to this doctrine. Thus, it makes it an odd choice for scriptural support for his view; he probably would have done better to argue for an eternalist reading of some hell passage. Consequently, McClymond’s reading of this passage to support his doctrine of hell relies upon the assumption that there are no further chances to accept grace after death.The only reasoning which McClymond seems to offer for this assumption is that no second chances makes life’s decisions more “meaningful.” But, this too is just assumed. Far more interpretive work needs to be done to support his reading of this passage.
Finally, McClymond’s charge that a true Christian who believed in the power of the cross couldn’t “even toy” with universalism is flat-out uncharitable. Just like in the rest of his lecture, he simply assumes that a true Christian theology must hold to certain positions, one such position being that God punishes the unrepentent in hell for all eternity. Universalism is thus ruled out as un-christian by definition and without any convincing arguments as to why this is so. McClymond mentioned that his substantiative arguments would be made in the book, but if the peeks at his arguments in the lecture are any indication, his book will be more of the same, tired traditionalist arguments against universalism, only with an odd “historical” genealogy tacked on as supposed support.
Really just pathetic jabs that don’t even break the skin of an even minimally well-formed universalistic position.
The Gnostic code by Walter Wink is a really good and balanced brief introduction that takes account of diversity and tries to read behind the polemics. 
)
. They like to accuse Christian Universalism of promoting cheap grace, but what they forget is that grace isn’t cheap (or costly, to us) it’s free! If it wasn’t free, it wouldn’t be grace at all. So this one is doubly bad, in that it’s essentially a false dichotomy within a straw man (or perhaps red herring).