Because atheists are so often involved in criticizing religion, sometimes very strongly, theists can develop the perception that atheism is a belief system characterized by being against everything: against religion, against theism, against Christianity, against God, etc. That people would develop this perception is understandable, but it's still incorrect. Atheism is only the absence of belief in gods; atheism does not entail being
anti-religion or even anti-Christian.
Debating theists is not necessarily an effort to convert people and, in fact, some atheists are themselves religious.
Atheism and anti-theism so often occur together at the same time and in the same person that it's understandable if many people fail to realize that they aren't the same. Making note of the difference is important, however, because not every atheist is anti-theistic and even those who are, aren't anti-theistic all the time. Atheism is simply the absence of belief in gods;
anti-theism is a conscious and deliberate opposition to theistic belief. Many atheists are also
anti-theists, but not all.
Atheists are often seen critiquing religion, so the perception can develop that atheism itself must be an anti-religious position — but this is not true. Atheism is simply the absence of beliefs in gods and is a position which can occur inside or outside the context of religion. Thus, an atheist might be devoutly religious, devoutly anti-religious, or completely apathetic with regards to religion — exactly as is the case with theists. It all depends on the individual and what ideas, beliefs, or principles they have aside from atheism.
Because
most atheists are not religious, it is understandable that most atheists aren't going to make an effort to raise their children in an explicitly and deliberately religious environment. Does this, then, mean that atheists are also trying to keep religion away from their children? Are they afraid of their kids possibly becoming religious? What are the consequence of hiding religion from someone?
Although this is by no means true of all atheists or atheism itself, there is some validity behind the perception that atheists are anti-Christian and it should be taken seriously. There is no ignoring the fact that many atheist web sites and atheist books spend a great deal of time with the doctrines and beliefs which are specific to Christianity or, at the very least, to traditional forms of Western monotheism while at the same time ignoring other religions and more general theistic beliefs. Why is that?
This is similar to the claim that atheists are anti-Christian because of the time they spend on critiquing Christianity; it is, however, a more general assertion and merits being addressed separately. Is it a legitimate complaint that atheists are bigoted when it comes to Christianity? That is to say, are atheists intolerant of Christianity, Christian beliefs, Christian institutions, etc.? Even if this is true, what impact if any does this have on atheism and atheists' critiques of Christianity?
Atheists in the West often don't have very positive feelings when it comes to religion. The reasons for this are manifold, but most have to do either with the role religion played in their families or the use of it by others to berate and evangelize to them today. As a consequence, individual atheists are quite often at least
irreligious if not also anti-religious.
This myth is based upon a misunderstanding of
what atheism is. Many theists think that atheists don't believe in anything at all; evidently, we have no goals, no ideals, and no beliefs whatsoever. Such theists cannot understand how it could be otherwise because their beliefs in and about their god often constitute the most important parts of their lives and are especially important when it comes to their goals, ideals, morality, etc. Without their god, then, those things can't exist.