Question:
Should I raise my kids as atheists?
Answer:
Christians raise their children as Christians, Jews raise their children as Jews, and Muslims raise their children as Muslims, so doesn't it make sense that atheists raise their children as atheists? That might seem to be the case at first glance, but in reality it doesn't make all that much sense after all.
To begin with, religions like Christianity, Judaism, and Islam are belief systems when you raise a child "as" a Christian or a Muslim, you are teaching that child that the world is a certain way, that they have a certain place in that world, and that there is a moral imperative to believing what they are being taught. This is a process of mental, emotional, social, and psychological formation based upon a complex system of beliefs, attitudes, and ideas.
Atheism, being merely a lack of belief in gods, has no parallels.
Another important issue is the fact that children are already born as atheists they have to be taught to believe in gods and to adopt certain religious systems. If you don't tell them that they should believe those things, then you are simply maintaining the status quo. In so far as it is even possible to raise a child "as" an atheist, nothing further is required.
But, you might ask, couldn't these children acquire theism or religious beliefs elsewhere? Shouldn't I teach them things to prevent that from happening? Yes, that it is true that they could acquire such beliefs outside the home and perhaps you would prefer that they don't, but there are a great deal of ethical and intellectual differences in the ways you might try to prevent it from happening and all of it involves teaching a great deal more than mere atheism.
If, by example or design, you raise your children "as" atheists by teaching them to ridicule the beliefs of others, you will only be raising them to be prejudiced and bigoted. They don't have to accept or agree with or even like the religious beliefs of others, but they shouldn't make a point of ridiculing those beliefs and treating believers as if they aren't deserving of the same respect as atheists and the non-religious. This will not only save them from unnecessary conflict, it will also make them better people overall.
On the other hand, you could raise them to be skeptical and critical thinkers. If you raise your children to be skeptical as a general rule, it won't be necessary to go out of your way to have them treat religious claims skeptically they should end up doing that on their own anyway. Skepticism and critical thinking are attitudes which must be cultivated across a broad range of topics, not just something to focus on the topic of religion but forget about otherwise.
Of course, that isn't actually preventing them from adopting religious or theistic beliefs which they learn about outside the home, because skeptical and critical thinking do not necessarily prevent someone from being a theist or being religious. It should, however, make the adoption of such beliefs less likely and, if any are adopted, those beliefs are much less likely to be extreme or traditional.
The question which needs to be addressed here is: are you more interested in your children simply not being theists or religious, or are you more interested in your children not being the sort who accept claims and beliefs uncritically or who don't think for themselves? The former is a type of intolerance and it simply wouldn't be ethical to raise a child in that manner.
The latter, however, is very ethical and a very good idea if every child were raised in such a manner, there is a very good chance that society as a whole would be better off. However, by raising them to think for themselves rather than to automatically reject some ideas, you are allowing for the possibility that they will adopt a position on theism or religion that differs from your own. If you are a tolerant and loving parent, you won't think any less of them for that.

