Fantasy series (trilogy?) about rival brothers with Kabbalistic elements

[Blanket]

The book was about two rival brothers competing for... something (to save the world?) Its setting was based on or used a lot of elements from Kabbalah and the Tree of Life.

The prologue and epilogue of each book was narrated by the winning brother (telling the story to his students?), but it was a big mystery about which one it was.

I never found out the ending because at the time the publisher refused to print the last book due to lack of sales, and wouldn't give the author the rights back either. I really hope that's changed.

I'm pretty sure the first book was written in the 90s, but the latest it could have been was about 2005. I doubt it was older than the 80s.

The cover wasn't full-art, but all black with a square in the middle with a man's face inside. It was not a very good picture.

[Lobstergirl, au gratin]

What country was it published in?
Religious publisher?

[Blanket]

Lobstergirl wrote: "What country was it published in?
Religious publisher?"

I bought it in the US, so probably there. I have no memory of the publisher, sorry.

[Capn]

Hey Blanket, are you still looking for this?

I was actually just about to post a "Suggest Books for Me" on the topic of the Kabbalah, and in a search this post came up...

Anything about Golems in it, perchance?