I believe that you have an unexamined assumption in your post. Namely, can you have any effect on what your child believes?
A book by Judith Rich Harris called "The Nurture Assumption" makes the case that it is not parents that shape a child's attitudes and beliefs, but the child's peers. Parents impact on children tends to be primarily genetic and in the basics (no abuse, well fed and clothed, and choosing the general environment where the child is raised.) For a more detailed look on Harris's argument, see Malcolm Gladwell's article at http://www.gladwell.com/1998/1998_08_17_a_harris.htm .
If you agree with Harris's argument, you might rethink your attitude towards your child's belief in God or Santa Claus. They will probably make up their own mind about it despite your best efforts.
Hope this contributes to the discussion.
David
JRH is mostly talking about the long term. Parents have little effect on their children's adult beliefs and behavior. They have an enormous impact on what they believe and how they act as children. One of JRH's examples that she brings out several times is what language is spoken fluently as an adult. We tend to assume kids get it from their parents, but that's a spurious correlation. Nearly all normal children are exposed to parents and peers who speak the same language, and the children end up matching both. When parents and peers speak different l...
Related on OB: Lying to Kids The Third Alternative
My wife and I are planning to have kids, so of course we've been going through the usual sorts of debates regarding upbringing. We wondered briefly, will we raise our children as atheists? It's kindof a cruel experiment, as folks tend to use their own experiences to guide raising children, and both of us were raised Catholic. Nonetheless, it was fairly well settled after about 5 minutes of dialogue that atheist was the way to go.
Then we had the related discussion of whether to teach our children about Santa Claus. After hours of debate, we decided we'd both have to think on the question some more. It's still been an open question for years now.
Should we teach kids that Santa Claus exists? This isn't a new question, by any means. But it's now motivated by this thread about rationalist origin stories. Note that many of the posters mark the 'rationalist awakening' as the time they realized God doesn't exist. The shock that everybody, including their parents, were wrong and/or lying to them was enough to motivate them to pursue rationality and truth.
If those same children were never taught about God, Santa Claus, and other falsehoods, would they have become rationalists, or would they have contented themselves with playing better video games? If the child never realized there's no Santa Claus, would we have a reason to say, "You're growing up and I'm proud of you"?