But I also see Christianity as a sort of aggregation of pre-Christian thought, both Western (which we call Eastern, i.e. Greek), and Eastern (which we call Indian, i.e. Buddhism).

The Middle East was a sort of borderland between the two, and I think Christianity encompasses and expands on both, and takes both to the logical conclusion. But it's important to recognize and understand the roots of Christianity as well.

I remove the “Zen” because that's a far later Japanese variation. The word Zen comes from the Pali word jhana, but it would be odd to talk about “Jhana Buddhism”.