I see the problem faced by someone who has been living a life of religion in a community of religion, and who depends on this life for his economic and social survival, and who then decides that he no longer believes in it. I have criticized his certitude, but I understand the situation as best one can without actually living it; as I noted in Part I, there was a time when I seriously feared I might end up that way, as well.
But living unethically is not going to solve his problem. It's not about Judaism or belief, it's about living a split life, and a deceptive life.
Michah 6:8 instructs us that Gd expects of us to, “Practice justice, love generosity and walk privately with Gd.”
Normally, we view the first two principles as social, and the third as covering our relationship with Gd. Rav Yaakov Ettlinger (19th century Germany, rebbe of Rav Shimshon Raphael Hirsch), though, saw them differently:
והנה פרט מיכה ג' דברים נגד ג' מיני מצות, שבין אדם למקום, בין אדם לחבירו, ובין אדם לעצמו. נגד לעצמו אמר עשות משפט, שישקול כל מעשיו שיהיו במשפט ושלא יהיה עול בכפו. ונגד בינו לחבירו אמר ואהבת חסד, שהוא גמילות חסדים שבין אדם לחבירו. ונגד בינו לקונו אמר והצנע לכת
Michah specified three activities, representing three types of mitzvot: Between Man and Gd, between Man and Other, and between Man and Self.
Between Man and Self – Practice justice, meaning to weigh all of one’s deeds to ensure that they are just, and he has no corruption in his hand.
Between Man and Other – Love generosity, meaning providing acts of generosity between himself and another.
Between Man and his Creator – Walk privately.
(Aruch l’Ner to Makkot 24a)
In other words: Justice is not only about ensuring the safety of those around me. Justice is also about ensuring my own inner balance. It's a responsibility to myself. This is one of the reasons why the great majority of atheists and agnostics live ethical lives.
So what can he do? I've known many people who have had to switch careers mid-stream - professors who received terrible student evaluations, businessmen who were cheated by their partners, stock traders who lost their shirts and their confidence. It happens.
Ofcourse, one difference between the cases above and that of the Orthoprax Rabbi is that these people were forced out by external circumstances; this rabbi has no external pressures, only internal ones. And on some level he probably tells himself that this could be temporary; he might still be able to return to his previous faith, rather than give up his trade.
Another difference is that those other jobs were primarily jobs, for financial survival. The rabbinate has so much family and social weight that it is much harder to leave the field.
But for his own health, aside from the ethical responsibility to his community I discussed in Part II, I think he would be better off looking into academia, administration and management professions, civil service, a transition to law school or accounting, freelance writing, anything rather than remain in the synagogue rabbinate. Tell the family and community it's because of the stress of the rabbinate. It's healthier for him, for his family and for the community that depends on him.