This is a profound and difficult philosophical question. I have toyed with the idea that it is wrong to teach children anything normative in the areas of politics and religion - at least they won't know enough to spoil dinner table conversation when they grow up. Seriously, I am not sure what the answer is, but I think that I would want to take my stand on a distinction between teaching by indoctrination and teaching by example. It is difficult to see that there could be an objection to people raising their children in a context in which the faith of the parents is evident. (But what happens when the child is to copy the parent in the recitation of the Nicene Creed? - "We believe in one God, the Father Almighty, Maker of all things visible and invisible . . ."?) And when it comes to explicit religious instruction, things can get sticky. As long as the transmission of the faith is restricted to example and reason, though, I think it is acceptable. When the method of transmission is authority and indoctrination, it is not, as I see it. Something destructive enters the picture.
Religious indoctrination involves very profound moral, emotional, and political implications which are beyond the grasp of young children. Isn't it wrong to indoctrinate a child into a religious belief before they can knowledgeably consent to the implications of that belief system?