I figure intelligence is as intelligence does. I never drank the kool-aid, so I don't fit your model of a former member, recently awakened. What helps me is self-editing as yadda yadda describes, which I learned from On Writing Well by Zinsser.
https://www.goodreads.com/book/show/53343.On_Writing_Well?from_search=true
It turns out that clear writing leads to clear thinking, and vice versa.
I was part of the debating team in junior high school, which likely says far too much about me already. (Geek squad!) That training taught me that both sides of an argument can be fought intelligently. I always put myself in the shoes of my antagonist, and work out my best defences against their (anticipated) best arguments. It is most disappointing when my opponent devolves to ad-hominem. There are always so many better arguments left to explore! A large failure in religious argument is to assume rightness of one's position by faith, failing to thoroughly case out the opponent's position. The apologist ends up playing the fool, while remaining secure in their faith, by assuming Satan's wily ways have foiled the way of light (lower case L) yet again.
I also recently took a reading test and it turns out I read twice as fast as the average Canadian, and trust me up here in Canada we have moved beyond scratching on birch-bark. That helps. My comprehension is good.
http://www.nationmaster.com/country-info/stats/Media/Personal-computers/Per-capita
I notice that posters often miss a salient detail in a newcomer's post. For instance, they may not notice that they are talking to a teen-ager, or whether there are children involved. These details matter.
