Primitive Christianity Revived, Again
Kirby Urner asked "what is a Quaker meeting?"
My answer: a Quaker meeting is, at its best, an encounter with God: Father, Son and Holy Spirit; a burning bush experience. In a Quaker meeting, this encounter takes place in the fellowship of believers, the community gathered in Christ. It is not a private experience.
God's overt realm is where Spirit rules openly, certainly from within, but also objectively all around and 'among' us. Where gravity isn't just 'the Law', but a general rule of thumb subject to compassionate override.
Religions are generally able to recognize 'Christ within'/'Spirit of God'/'Buddha Nature' etc and recommend practices for cooperating with that, towards developing the harmony between 'me' and 'all that "Out There"!'
But God's realm aka 'The Kingdom' is not some human construct or community -- but universal enlightenment and life within the paradisical norm hinted at by Biblical allusions to 'Eden' & 'New Jerusalem.' That's pretty much a Christian thing, often inconvenient -- and disappointing whenever people set out to make it happen with our ego-muscles... but what we yearn for, when we dare yearn.
Mystical teachings regarding the Kingdom's immanence coincide more closely with say a Zen master's fascination with the Void or Suchness. "If you didn't have that ego, you'd be home by now" is the Buddhist billboard, reminding of the Samsara == Nirvana equation.
For Christians, the Promised Land tends to always be in the future, perhaps in some promised Afterlife. This sets up the ongoing temporal struggle to "get there" someday, which then becomes the saga, complete with a projected Rapture-plus-Apocalypse (it's hard to imagine Christianity minus its doom-saying, so integral to its hellish imagery).
Christianity tends to discard this world as "already fallen" a "lost cause" and many Christians yearn for some world beyond the grave, which they tend to be incoherent about, unless able to paint like Hieronymus Bosch.
I'm skeptical of equating the immanence of the Kingdom with the 'void' (shunyata), or emptiness, of Buddhism. And the idea that samsara = nirvana is a specific sectarian teaching of Buddhism; not definitive of Buddhism.
Personally, I see a bridge between Buddhism and Christianity by focusing on ethical commitments and the nature of dependence. The basic ethical commitments of the 5 basic precepts of Buddhism (which all Buddhists are expected to live by) and the 10 commandments to be fairly close; and they both have versions of the Golden Rule.
Both Buddhism and Christianity regard things as dependent in their ontological status; lacking in self-sufficiency. For Buddhism this is derived from their analysis of causation. For Christians this is derived from the nature of creation, that God created all things and that therefore things are dependent upon God for their existence.
These two similarities are significant and provides a basis for communication between the two traditions. In other respects, though, the two traditions differ and the nature of emptiness, whether emptiness is ultimate, is one of those differences.
There are Christians & Christians; but Jesus, by the earliest and most coherent rendition of his life, was proclaiming one basic message: the immediate, ongoing onset of the Kingdom of God (aka the restoration of Israel's covenant and God's active participation in the world -- which would develop to include all humanity and the entire Earth).
His ethical teaching -- like much Hindu ethical teaching and much Buddhist teaching -- was intimately related to that central proclamation. If the Kingdom is here, and anyone with sufficient faith can rearrange the landscape, one needs some ethical safeguards. People with miraculous power and unbridled lusts & rages go together like gylcerin and nitric acid (usually overheating and fizzling out -- but quite explosive, if that combination were to continue long.)
I welcome your skepticism and your scholarship. In what I call "Rabbinical Quakerism" we might go on and on until the cows come home (full moon + lunar eclipse tonight!) debating whether God's Kingdom or The Void is the more satisfying eternal ending (I find monarchical language somewhat tiresome, a turn-off, but that's just me; I'm maybe less of an Anglophile than most Friends in that way ).
A lotta Quakers seem to shy away from debate or controversy of any kind. Not me, and that my younger daughter was a state champion in Lincoln-Douglas debate (competing nationally) continues to fuel my pride as her father. Rabbinical Quakerism celebrates building up the archive of scholarly commentary, just like we're doing here.
Another connection twixt some Buddhist sects and Quakerism (likewise sectarian) is emphasis on "practice" over "beliefs" or "dogmas". My late wife used to look at me askance if I tried to offer up any Buddhist credentials -- studied it at Princeton, liked Alan Watts... or even: est-trained -- as at the end of the day I didn't practice enough, in the sense of Zazen (just sitting), as she did. Dawn Wicca, not a Christian, but definitely a Meeting member, was also a huge reader / scholar and loved studying the life of Jesus and his friendships with the strong women in his life.
Quakers likewise put a lot of emphasis on attending Meeting for Worship (practice), not just committee work (more "head strong"). What comes out of one's mouth is just so much "head belief" i.e. theology is sometimes devalued in Quaker scripture as just more "brain fudge" or "yadda yadda". That's partly what makes 'em good diplomats, those Quakers. They don't immediately bristle when exposed to "wrong views" like the more dogmatic might -- what some take as evidence of their Liberalism (as in "less strict about adhering to orthodoxies").
I resonated with Karen Armstrong's book Battle For God in that she likewise stresses how Protestants in particular seem obsessed with Thoughts & Cogitations as a means of salvation i.e. it's a matter of picking up the right Talk, whether one has a Walk or not. You need the right Credo, so that you know how to say the right things in polite company. Your Christianity is defined by your vocal chords more than how you spend your time and money (just stay comfortably middle class at least and you'll be fine).
Quakers, for me, are refreshingly less obsessed about mental machinations as definitive of their spirituality and identify more with practice instead. That sets them higher than mere run-o-the-mill Protestants in my book, with some of the saner Friends escaping the Protestant vortex all together, praise Allah.
Some sects within Islam and Judaism are quite similar: it's the community feasts, fasts and festivals that matter most (participation), not all that garbage about "God" rattling around in your head (aka "theology" aka "mumbo jumbo"), "God" being a dependent concept (lacking self-nature) if there ever was one. As we say in Zen "holy scripture" is just so much toilet paper in the rear view mirror, once you're truly free of all those stinky concepts and overthinking everything (just another form of vanity, no?).
A couple well-meaning Christians came to my door the other day, drumming up interest in a local congregation. Their opening question was did I know for a fact that I was saved and would be going to Heaven? My answer: "I don't want to go to heaven, I like it here and plan to come back." Braaaap! (game show buzzer sound) wrong answer! This was not the time for Rabbinical Quakerism. I'd gone off the script.
Fortunately my housemate, raised a Southern Baptist, came to my rescue. She came to the door and put her arm around me saying brightly "We believe in Jesus Christ as our personal savior" and that put the remainder of the conversation on an even keel, as now the script was being adhered to. We waved goodbye to the good sheep of this particular flock (after they prayed for us some more) and all was well with the world. Good little Xtians are so cute sometimes. 
Said housemate Lindsey has since flown back to Kathmandu where she's a student of esoteric Newar Buddhism (a few blocks from here is the only such temple outside of that area -- they practice a form of dance as a primary form of transmitting Buddhism, and she's learning it). Like I say, this part of Portland is sometimes called "the Buddhist ghetto".