Some born & raised have attended a service or two at those "false churches" (usually reluctantly for something like a family funeral, or even to impress a potential recruit that they are "open minded"). However, the more hearty are so focused on externals (such as the church building, wearing of stylish clothes, etc.), that they almost immediately find confirmation of the indoctrination to which they have submitted. I don't think many "innies" are open, Bible-literate or interested enough to seriously evaluate much beyond superficial appearances. These experiences tend to confirm their upbringings, and the accounts get whispered about to spread that confirmation to others of the friends.