I found it: this is the post I meant.

Thx. That is a good posting. As was the posting to which it responded

You need convincing arguments against religion as its practitioners see it.

I'm confused. I just want to understand religion, and the world in general, better. Are you interested in deconversion?

Whoops! Bad assumption on my part. Sorry. No, I am not particularly interested in turning theists into atheists either, though I am interested in rational persuasion techniques more generally.