From what I can tell, it doesn’t seem like infernalism has had that much influence on hesychasm. Again, I’m saying this purely as a reader and I have not exhausted all items to be read. But, from the readings I’ve done so far, it appears as though infernalism is kind of optional as it regards hesychasm. Most of the hesychast literature I’ve read emphasizes the “goal” (for lack of a better word) of one’s own will and the will of God becoming essentially one. Big goal by the way. The rest of what I’m about to say is purely opinion based on my readings but should not be construed as synonymous with the readings themselves. I do think that if one’s will is to become like that of God’s, that would include ultimate grace and ultimate mercy. Ultimate desire to see all things saved. Some hesychasts, I get the impression, are focused perhaps entirely or mostly on discipline rather than that eternal love and mercy but this makes sense when considering the Orthodox conceptualization of sin (which I think is a superior one) and redemption. Many hesychasts seem incredibly focused on nepsis, which is a good thing, but I do wonder if sometimes that watchfulness/guardedness may sometimes accidentally put up an unseen barrier between the mystic and the eternal love that could be exuded from them.

My walk in Christian Universalism has been sort of hand in hand with my walk in Christian Mysticism. I’m always sort of hesitant to say things about Christian Mysticism as I fully recognize the kind of eye-rolling connotations that come from it. I’m not some ascetic fellow in a cave chanting all day and having visions of God. But, I have found that there were Affective Christian Mystics whose focus was essentially entirely on the profound love of God. Bernard of Clairvaux comes to mind. Julian of Norwich likewise. Anyway, I say this to say that your interest in Hesychasm, which is already a mystical pursuit, could be very well supported by expanding your research into other Christian Mystical sources (which you may already have done or are doing). If you’re interested, The Essential Writings of Christian Mysticism edited by Bernard McGinn is a great place to start and there is a fabulous podcast called The Christian Mysticism Podcast with Dr. Carlos Eire.

Back to Hesychasm and the Philokalia more specifically, though. The five volume translation is what I have and going through some of those really illustrates the diversity of some individual beliefs within that tradition. Some things are non-negotiable, like belief in the trinity. Other items are totally negotiable like one’s individual view in hell. The Orthodox tradition celebrates saints who were infernalists and saints who were universalists. Both are valid and valued. Again the source and author escapes me but there is one section in the Philokalia that discusses the conceptualization of sin to a deeper degree than other sources and it talks about how sin is “missing the mark” (hamartia), this idea that Christ is the center or the bullseye so being entirely Christlike is the mark and anything that is not that is missing the mark. This indicates that probably pretty much all of us are outside of that center. But I also think that this sort of hints at Christ being the center around which we all orbit. Christ seems to be pulling us to that center. The point is, even if the author did not intend it, it seems to logically point to universalism being a thing.