I'm so sorry to hear about your son. What motivates him? Why has he joined and quit anything else in the past? For me, I am very values-driven and I finally left the LC people I loved and respected pointed out that the LCs were promoting values I strongly disagreed with (precisely, denigrating other Christians and reading books from only one source). One of my brothers is highly motivated by feeling respected and he finally cut ties when a leading brother publicly cut into him at a meeting after he had put his heart into sharing. Another of my brothers is motivated by loyalty and left after someone he cared about was shunned.
The book "Leaving the Fold" by Marlene Winnell was incredibly helpful to me as I left, and understanding how others can safely leave high-demand fundamentalist religions. Some find her therapy methods questionable but the first part of the book helped me pick apart why the LC had been so important to me and what I was going through while leaving.
"Girl at the End of the World" by Elizabeth Esther made me laugh and cry about growing up in an elitist fundamentalist group. She and her husband finally left due to unchecked physical abuse and she, interestingly, became a Catholic.
This
article about how Megan Roper left Westboro Baptist Church is one of my all-time favorite reads. It gives me hopes that anyone can be saved from cults and cultlike environments. It also give me hope that I too can turn my life around from the selfish, self-righteous, wretched, judgmental person that I was in the LCs. There are many years ahead of us to heal, be forgiven, and live strongly.