Other perspectives on deification and Quakerism
I'm far from the first person to write about possible connections between Eastern Orthodoxy and Quakerism.
Carole D. Spencer, in The Creation of Quaker Theory: New Perspectives, an unfortunately expensive book (with some fascinating pieces in Google Books, fortunately!), writes on The Essentially Orthodox Nature of Quaker Holiness:
The concept of deification, unio mystica, a participation in God through Christ, is the foundational experience of all Christian mystics and has always existed within, and alongside, the dogmatic, liturgical, and institutional faith. This mystical aspect of faith, as divine union, biblically expressed as 'partakers of the divine nature', (KJV, 2 Peter 1:4) was so central to the beginnings of early Quakerism that one leader, Richard Farnworth, actually made it into a ditty, "Written by one whom the world called a Quaker, but is of the divine nature a partaker."
This experience-based faith was anchored to (and indeed could not be understood apart from) the mystery of the Trinity. Fox cared nothing for the dogmatic formulations, but the experience of the three persons, God, Christ, and Spirit, and the ultimate unity in the diversity of persons was paramount. This experience-based faith was also anchored in the doctrine of the incarnation, the Word becoming flesh, and the atonement, Christ's offering on the cross. The key biblical text for Quakers, John 1:9, 'the true Light that enlightens everyone' could not be understood apart from the incarnation, because the true Light was the Word become flesh. And Fox, like the Greek fathers, did not stop there, but recognized the inverse as well, that transfiguration was a two-way process. Since Word (God) became flesh, flesh could also become God-like (deified, perfect)....
Fox understood perfection as the return to the original God-likeness in which humanity was created, which Christ had restored through his incarnation and atonement. This concept of perfection as restoration and earthly glorification, rather than a glorification only to be experienced in eternity, is common to Christian antiquity and continues to be the traditional understanding of holiness in the Eastern Orthodox Church. (160-1, emphasis mine)
(Update: I knew I'd seen Carole Spencer's name before, and I probably found myself on this track because of her writing in George Fox's Legacy, where she discusses similar themes of Orthodox deification before looking at more specifically Quaker holiness, starting from Hannah Whitall Smith.)
In the blogging world, Larry at Reflections of a Happy Old Man wrote on deification and Orthodoxy in 2005, and Johan Maurer writes about Orthodoxy periodically.
And for a different take, see John Oliver's From Reason to Truth to Mystery: An Odyssey to Orthodoxy follows the writer's path from Presbyterianism to Evangelical Quakerism to Orthodoxy. There's an interesting if brief anecdote near the start:
At first blush, Quakers and Eastern Orthodox seem to have little in common. Yet here, as in other matters, I was light years behind Orthodox theologian Alexander Schmemann who, placed at a conference with representatives of liturgical traditions, said "Oh no. Orthodox belong next to the Friends."
I'll have more on the Orthodox side up next.