I don't mind discussing it now and Zen. ;P
I followed such a path for a while and found it very helpful. I became calmer, nicer to live with. Happier (or perhaps 'more contented' is a better way of putting it) too. All through the Buddha's suggestion to 'suck it and see' (OK, I paraphrased there a bit).
I've never had a belief in deities (though I consider myself 'spiritual' along the lines of all that 'inter connectedness', one-with-the-Universe stuff) so I'd say you can be an atheist and practise Zen.
As for Christianity, well, Zen seems to have different ideas about dualities. 'Good' and 'Evil' are more .. relative concepts. And I can't see the idea of being born into sin and requiring salvation really fitting into the Buddhist worldview.
So while the meditation techniques could be used by pretty much anyone; since like yoga or tai chi they can just be applied practically, I think it would be difficult to combine Christian beliefs with Zen concepts such as nirvana, 'suffering' and 'enlightenment'.
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