In his book "A Manual for Creating Atheists," Peter Boghossian has some advice for those who want to helo cure religious addicts: don't focus on weaning them off of religion; rather, remove the foundation of faith that supports their religiosity.
Attacks on religion are often peceived as attacks on friends, families, communities, and relationships. As such, attacking religion may alienate people, making it even more difficult to separate them from their faith.
...Attempting to disabuse people of a belief in their God(s) is the wrong way to conceptualize the problem. God is the conclusion that one arrives at as a result of a faulty reasoning process (and also social and cultural pressures).
The faulty reasoning process -- the problem -- is faith.
Positing make-believe metaphysical entities is a consequence of a deeper epistemological problem. Belief in God(s) is not the problem.
Belief without evidence is the problem. Warrantless, dogged confidence is the problem. Epistemological arrogance masquerading as humility is the problem. Faith is the problem.
...In other words, focus on undermining one's confidence in how one claims to know what one knows (epistemology) as opposed to what one believes exists (metaphysics/God).
Instead of having a discussion about the actual existence of metaphysical entities that can neither be proven nor disproven, direct the discussion to to how one knows that these alleged entities exist. (This may also avoid one of the most common retorts among uneducated, unsophisticated believers, "You can't prove it not to be true."
As noted in this post, Boghossian aptly describes faith as pretending to know things you don't know. Which isn't a virtue. But neither is it a vice. I like how Bogossian says we should divorce belief from morality.
Faith is an epistemological error, a problem in knowing what is true. Thus it stands outside of the realm of morality, notwithstanding the contention of religious people that having faith is a virtue. So, says Boghossian," having faith doesn't make one moral, and lacking faith doesn't make one immoral."
He gives examples of well-known atheists who most would consider moral: "Bill Gates (for donating his vast fortune to charity) and Specialist Pat TIllman (for abandoning an incredibly promising football career to give his life for his country)."
Here's the shortcuts Boghossian says he uses when he doesn't have time for a full Socratic discussion with a faithful religious believer.
First, I'll ask "How could your belief [in X] be wrong? I don't make a statement about a subject's beliefs being incorrect; instead, I ask the subject what conditions would have to be in place for her belief to be false.
...Second, I'll ask, "How would you differentiate your belief from a delusion? We have unshakable testimony of countless people who feel in their heart that the Emperor of Japan is divine, or that Muhammad's revelations in the Koran are true. How do you know you're not delusional?"
...Simply causing one to recognize that their core beliefs could be delusions may help them recognize the delusions.