Duvid… there’s nothing christian about saying that we are not god and that He has not divided himself into parts. Also, it’s the Arizal, bot the Tanya that uses the expression. And it’s “mamash mamash”, not just one mamash.
According to the way my rebbeim explained it to me, it’s not difficult – there is a piece of literal godliness within us, it is not a part of Hashem himself, but a holy spark from an infinite flame, so to speak.
Christian theology in its current incarnation among evangelicals is that god manifested as yushke and that everyone who believes in him has yushke and therefore god inside them. This is actually cery, scarily similar to how chabad views the last rebbe.
When a kabalah sefer says something that goes against the 13 ikkarim, we must say that we are misunderstanding the kabalah, which itself was never intended to be understood by the uninitiated. Many gedolim believe that the time has come to reveal kabalah – but they do not hold that one should let himself be hefker and read every sefer and come to whatever conclusion he wants. There needs to be a mesorah. Chabad broke that mesorah and are very independent in their learning of kabalah.
The only way you can severely disrupt Torah philosophy is through kabalah; that was the downfall of shabsai tzvi, frankel….lehavdil rabbi kook, all was made possible through reckless use of kabalah (and haskalah, in the latter’s case)