Actually that also brings up the issue of distinguishing between the person or at least a self and their belief sytem. Since people can change their beliefs, obviously there is someone there besides their beliefs no matter how firmly held it is. There are a ton of details you can talk about but frankly discussion around teachings and doctrines feels rather like a "brute force" kind of approach and seems to subscribe to a belief in a quantitative approach where you (sometimes literally) exahaustively approach every single thing there is.
A psychological approach, on the other hand is like recognizing that there is such a thing as firmware for your computer which works on a deeper, more fundamental level than even the operating system. The nice thing about people is that even when the existing OS is still running it is possible to point to how the Basic Input/Output System is functioning, so to speak, and that one can actually reprogram that. It actually ends up being a lot easier to deal with than all the code of the belief system, although you do have to look at things in terms of that basic process.