we as adults tend to attribute adult abilities to children. If were are talking about evangelizing to children. Developementally they don't even start using serious rationalization skills until the age of 11. They are hardwired to acquire language, culture, etc... it really does not matter the force with which a parent, society, school, pressures a kid to do this or that because they are already hardwired to aquire what they are exposed to. By not pushing an agenda they aquire the agenda of not pushing an agenda, or rather they aquire the agenda from elsewhere, normally the area in their life in which the agenda is most aggressivly pushed. Thus the reason why so many schools and education systems assume the role of parent, and the reason why after the age of 10-11 a peer group's agenda most often supplants those of a parent, or religion.
In children there really is not that much grey area, one needs to rationalize a grey area. Look at it like a circuit, it is eithger opened or closed without a medium to filter the input (rationalization). This is not to say children are stupid or can't think, or do not operate by an inner logic, they do and have skills to do so, if not they would all be run over by cars having never learned the rational skills not to look both ways before crossing a street, yet much of this is almost pavlovian, as any one who has raised a child can testify, sometimes they are the most sage beings on earth but more often its a never ending cycle of "I don't know why you don't understand that leaving your socks on the floor will get you in trouble every time!"
In adults however who can rationalize, as I said before, once an ideal is fossilized there is no more need to waste precious cognition power to re-rationalize the ideal every time something comes up concerning it. It then becomes an operational dogma.