The point im trying to make is that there probably aren't a lot of serious atheists who go on to convert to religion; its a cognitive step that, once made, is hard to take back.

As a former serious Atheist who could currently be described as religious, I can confirm that this is true - I do not think I have ever met anyone else who went from Atheist to Theist. In my case, it required - as you said regarding the Liberal to Communist transition - further information about the world that I lacked when I was an Atheist. Granted, I am somewhat unusual in this respect, as I was raised as an Atheist unlike most in America but - even still, it required what I perceived as hard evidence that there was more than just the material. Of course, this perceived hard evidence came in the form of personal experiences that I cannot transmit to others, as typically seems to be the case with this stuff, for better or worse.

This often also seems to be the case for the Liberal to Communist transition - I'm not sure I've ever seen someone actually be successfully convinced through rhetoric alone - it always requires some kind of personal experience that provides a bedrock of hard evidence that their current beliefs are inadequate for understanding and navigating the world in which they exist. After that bedrock exists - then rhetoric and reading and all that can have a meaningful effect.