From Owen Barfield on CS Lewis (1989) ed. GB Tennyson, page 13:
Lewis had spent his early manhood striving in all sincerity to experience living what Alan Watts has called 'The Supreme Identity'.
Lewis's very success in that endeavour - compared with the average run of idealists, who do not even make the attempt - proved to him that insofar as the experience is genuine and not merely a complacently fancied experience, it reveals itself as a theoretical truth but a pragmatical error.
It is and can be an intellectual experience only.
When it comes to the will, there is no identity, and the prayer must always be 'They will be done', just because my own will, if I look it squarely in the face, is a rag-bag of lusts and feeblenesses and terrors.
Not for Lewis, therefore, are the lofty strivings of the twentieth-century Buddhist and his condescending smile as he contemplates Christianity and all other formulated religions.
This is also my conclusion. That 'twentieth-century Buddhists' - i.e. more generally Western advocates of Eastern deistic religions - are (to use another and blunter terminology) complacent hypocrites (i.e. do not rigorously practice what they preach) and self-aggrandising advocate of the dark side (because they refuse to acknowledge and repent their lusts, feeblenesses and terrors).
Harsh, I know; but that is my evaluation - on similar grounds as Barfield describes for Lewis. Here and now and for us; Buddhism and the like are not just an ineffectual spiritual dead-end; but an inducement to self-justified embrace of the dark powers - and thus associated with joining and fighting-with the wrong side in the unavoidable spiritual war. (As did Alan Watts.)
For us; God must be personal, and our religion must be Christian. No alternative. Doing this - each of us, for his own life - is not straightforward; but the conclusion to be drawn from such difficulties to get to work on making it possible.