When I started my main character, I chose to be an athiest. Now, I find ways to rp that. I won't say that the gods don't exist. Serq isn't crazy. Instead he believes that the 'gods' are merely powerful wizards of a very powerful race, or to some similar effect. He acknowledges their presence in Yliakum, and gives respect to them for their power in creating worlds, but doesn't feel that he should blindly follow someone, no matter how strong, without any evidence specific to him that he should. Serq will also point out that there are many mages already that can probably become almost as powerful if they had a few more glyphs that could allow this.
I haven't read all of the books in the game, so my opinion might be a little biased. I don't think that Serq is in any danger of being labled an infidel because he gives proper respect, but I'm unsure how it would be taken on a large scale. What do you think? I can't speak for all of the aethiests in Yliakium out there, but I think that many of them feel this way also.
By the way, I'm not aethist.