At what age should a child be introduced to religion?

[emjay]

Honestly, it depends on what "to introduce" means.

"Daddy, what's that building you go to every Sunday morning?"
"Sorry, Timmy, I can't answer that question until you're 12 years old."

"Mommy, what's that pendant you wear around your neck?" 
"This is not for you to know until you reach the age of reason. Ask again then."

Do you personally make any distinction in your mind between how a person arrives at their beliefs/faith? And do you think God, if he exists, does? Ie is faith/belief arrived at through curiosity, critical thinking and weighing up the evidence equivalent in your and/or God's mind to belief/faith arrived at let's say passively, not through curiosity or any act of will but instead through repetition and the trusting nature/suggestibility of youth?

That's ultimately my problem with all of this. If belief is all that matters in Christianity, not how it's arrived at, then basically that strikes me as both incredibly unfair as well as unrealistic to expect of a God to make no distinction between the two.

Now I'm not saying that all teaching of religion is indoctrination, deliberate at least, or that it can't come from good intentions... my own parents for instance, very loving, and brought me up as a Christian... I don't consider myself 'indoctrinated' in the worst sense of the word, but at the same time, when those beliefs were arrived at passively, basically soaked up like a sponge, as children's minds can be likened to, can or should that basically default/implanted belief really be considered true belief, and from a Christian point of view, be just as valid on Judgement Day as reasoned belief?

As to the OP's question, it's not something I think should be legislated on or whatever, or be as arbitrary as your parody implies, but just thinking about what could have helped in my own upbringing; I just think it the main thing is the delivery; ie don't state as fact that which is belief. Just that tiny little behavioural difference, no matter how strongly you believe in something yourself, and is thus essentially fact to you, I think could make a big difference... 'I believe this... other people believe that...'. I don't have kids but if I did I'd hope I could remain mindful of that.