Actually, you know, on a serious subject:

There's still a LOT of religion in FFX-2. While the world is different, there's a new religion--New Yevon--cropped up in Yevon's place. A lot of people have gone back to it because of the void of Yevon and how it affected every single second of their lives. As someone who has left their religion, I can say it's very traumatic. To have it torn away from you without your consent and thus taking the only life you've ever known? I really can't imagine. So, of course, New Yevon takes the helm.

But then there are people who are dissatisfied with religious abuse and the way Yevon controlled their life, and so they start their own group--The Youth League--which is basically the atheist group who wants to figure things out on their own but are undisciplined because of their new found freedom, disillusionment, and need to control others. Despite not being religious, they're still a new 'religion'.

And seeing how there's an entire chapter (chapter and a half) surrounding this plotline, I don't know you can say that religion doesn't play a major part in FFX-2. Even if there weren't new religions, there would still be the hole left by the downfall of Yevon, so religion would still be directly affecting the course of the story.