That is pretty true actually. Both are deep seated beliefs with no evidence that you can’t convince the person of not being true no matter what you do. They have to change their own mind.
cc: @Minnii @mortimermouse
The pros tend (overwhelmingly) to see the self-as-God delusion as a very understandable attempt to compensate for intolerable psychic injury / deficit / incapacity by trying to believe they are omniscient and/or omnipotent.
CBTs (and neo-CBTs) like those listed below work very well for this syndrome IF the pt is well-stabilized on meds, has recovered a pretty good level of cognitive functioning most of the time, and has a solid support system outside his or her nuclear family of origin.
REBT – https://en.wikipedia.org/wiki/Rational_emotive_behavior_therapy
Schematherapy – https://en.wikipedia.org/wiki/Schema_Therapy
Learned Optimism – https://en.wikipedia.org/wiki/Learned_optimism
Standard CBT – http://www.beckinstitute.org/what-is-cognitive-behavioral-therapy/About-CBT/252/
MBBT – https://www.newharbinger.com/blog/introduction-mind-body-bridging-i-system
MBCT - http://www.ncbi.nlm.nih.gov/pubmed/22340145
ACT – https://contextualscience.org/act
10 StEP – http://pairadocks.blogspot.com/2015/04/the-10-steps-of-emotion-processing.html