This is an old one, but I thought I’d share it just in case you hadn’t seen it yet. A couple years ago, somebody asked the following question on Yahoo! Answers:

What is the best way to stop your child becoming an athiest[sic]? I don’t want any of my children to be punished by God. -JT (user no longer exists)

Most of the answers given were about what you may expect, following the “don’t scare them with religion/leave it up to them” route, but one particular answer must have charmed the pants off of everybody else, because it was chosen (by other users; not by the original asker) as the best one of the bunch:

Do not educate them, or expose them to critical thinking, logic or science. Lie to them constantly about how the world works. Feed them a steady diet of mumbo jumbo dressed up like real knowledge – the jumbo jet in the whirlwind for example – and pretend that it is deep wisdom. Make them loathe their own natural bodies and functions. Convince them they are small and weak and worthless and need redemption. Tell them everything enjoyable is grievously wrong to even think about, and that their only fun should be in grovelling to an invisible friend. Ensure that they resent anyone who is not like them in every way – skin color, nationality, political opinion but especially creed. Make such people out to be evil and vile and give them – impotent minorities all – the fictional power to somehow oppress and persecute the vast majority who do think like you. Teach them to laugh at and dismiss out of hand any faith but their own. Early – early mind you – make sure they are taught the difference between superstitious deadly error – that one raving lunatic in the desert told the truth about a vicious god who killed people, and divine eternal truth – that another raving lunatic in the desert told the truth about a vicious god who killed people. Instruct them with all severity and import to never question for themselves – to never think for themselves – to never live for themselves – but to seek answers only in one – just one – particular set of semi-literate bronze age folk tales. Above all – and this cannot be overemphasized – make sure they cannot spell, use correct grammar, or understand basic English words. That should do the trick. –David M

I think the final sentence about spelling and grammar was a bit unfair. Sure, a lot of theists show a particular lack of finesse in that department, but so do plenty of atheists. But it is what it is; despite that unnecessary jab at the end, I probably would have voted it as the best answer as well. Here’s a link to the original question/answer on Yahoo! Answers, so you may read some of the other answers offered to JT’s question.