<human>: Give me the gist of the text in a nutshell

Raised fundie till 15, then family stopped talking about religion, I assumed they kept their fundie views.  Told them I was atheist this weekend, found out that fundie was just one of a series of phases in their lives from hinduism, new-age beliefs, aboriginal mysticism, to fundamental christianity, to now some wierd christian/spiritual hybrid in which the bible and christianity have perverted Jesus' teachings, the true version of which are now lost forever.
 
I don't know how to talk to them, but I want to.  I have three siblings and we all have serious issues that lead back to our upbringing.  No one else is talking to my parents so I want to start things off and see if I can maybe raise a real family up out of the dysfunctional heap we are.

My problem is my parents will not talk rationally to me, taking away every tool I have.  I want to debate the parts of christianity they still hold true, such as creationism and just that the whole thing is divinely inspired.  But I am met with arguments like "I know because I know" "God tells me", lots of talk about how we are surrounded by demons and angels, stories of times when demonic forces have been evident, (never directly to them, always a friend etc.).
<bot>: Does anyone have advice for bridging the gap with people who don't care about conventional arguments against christianity because all of the evidence they need is in their own head?