We just got through discussing the necessity of baptism in John 3, pretty fundamental concept. The identity of Christ is a matter of interpretation; the early Church spent several centuries combatting christological heresies, and we still have the Latter Day Saints belief system, and all read the same scripture. A child could read the scripture and know enough on his level of understanding, but if his parents are heretical, the child would most likely grow up a heretic.
heroic whistle-blowers [...] I thank God they were priests.
I am actually not sure if Calvin was ever a priest. In the case of Luther, I think that before his apostacy his contribution was positive as he posed important questions that needed answering, but that would not have set him apart from numerous Catholic reformers who remained faithful and produced the necessary reform at Trent. His rebellion, desecration of his vows and the mutilation of the Christian Canon did nothing good to anyone.
Oh, I dunno. You have us. :O)