Don't believe it? Fine, don't believe it. Cayden Cailean is not a god of forcing people to believe things. Only tell your friend (your friend, not the authorities, there will be many other rumors to reach spies alongside that one); say it to your friends in the same drinking session that recounts lewd stories of the orgiastic rites practiced by Sevarists in Kelesh; laugh about those stories, but laugh with them also about the story that names a day and hour to look up to the sky and hope. You don't believe it, but surely many others do; and won't they feel stupid, come the day, ha ha?
Even a god as weak as Cayden Cailean can work a phenomenon like that on Golarion - for some short time before being caught - if He's willing to spend down His strength on it to the danger point, and sentence Himself to inevitable death for treaty-violations.