I am unfamiliar with the Gods you mention, but I am familiar with the concept of faith in a higher power than myself. I think you'll find there is truth to be uncovered in stories that prevail for quite so long like those of Gods and Saints.

[Inej was alive during the time of one of Ravka's newest Saints, she has no reason to believe it was all farce. If it could be true in her own world, why not this one as well? There's something to all of this, even if she doesn't have enough of the pieces to see the picture yet.]