I've seen a few bloggers write how religion/belief in God is a meme. I'm not so sure I agree with that.
First off, I've read the God Delusion and The Selfish Gene, and am assuming those who wrote about memes also have. On the book God Delusion itself, I will say that Dawkins displays considerable intellectual arrogance and I don't really like him, champion of atheism or not. That's one of the great things about the secular world - you can criticise the "greats" without fear of a slap from God - or more likely, your rabbi.
It was Dawkins who introduced the meme and he stated a number of reasons as to why he did. The first was that is sounds like 'gene.' Another was that it was supposed to be analogus to the gene in 'structural make-up' and behaviour - that it finds a host and replicates (the gene equivalent of finding a mate and having babies).
The single most significant flaw in this reasoning is that culture is not bits of infromation floating around. Neither is it analogus to the gene in 'structure.'
What is more accurate to describe the fact that religion has propogated itself so far and for so long, at least in my opinion, is a combination of social/moral cohesion and violence.
Social cohesion means that a number of people in a single society are all forced to stay together and keep the traditions and values of that society, by society itself. Whilst that sounds rather odd in abstract terms, since if all individuals wanted to leave society, you'd expect them to be able to do it, for at first glance, it is the individuals who make up society. But in practise, the truth is different.
Take the Jewish community for example. Someone who grows up in a Jewish community will replicate the behaviour of the people in that community. If their behaviour differs from the norm, they will be put back in line by members of the wider community. That could be a parent, a teacher, a friend, a neighbour or a complete stranger who tells you off. This is all due to the effects of cohesion - keeping people together.
Of course, physically leaving the community is difficult, for the indivdual has been integrated into society to the extent that they rely upon it and should they leave, their social and perhaps economic lives will fall away...until they rebuild in a different community which has different values. Of course, the society will continue to function after the individual has left and the community will barely feel the absence of the few who are able to resist this cohesion.
Think of it in terms of quicksand. The longer you stay in the same swamp, the deeper you go in, the more the effects of cohesion, the harder it is to remove yourself. It's possible, just difficult.
Therefore religion is not merely an abstract bit of culture, an idea which has been passed down generations: it is a reinforced way of life which isn't "transferred" to the next generation - the next generation is automatically born into it and necessarily imitates the behaviour of those around them.
Violence is a part of it because that's how religions have tended to remain alive and/or grow. For example, Islam. Sikhism. And just about any other religion...they've all had violent pasts as far as I can tell.
Perhaps this gives a greater insight into the Darwinian necessity of religion than does the concept of a meme. Afterall, the idea of a meme is too abstract to understand why a particular meme would be replicated. This theory (which I'm sure belongs to Weber and that I've done it a great injustice) suggests survival of the individual - the individual now has a community to rely upon. It also suggest the survival of the community, in that the society will always have a membership and those members will remain loyal to that particular community even if it makes contact with other communities.
In short, individuals have little choice how they act, as they will usually only ever act within the bounds of a certain community. If your parents are Jewish, you'll end up being Jewish. If parents vote republican, it's likely their kids will too.
Incidentally, people are therefore predictable and we can therefore begin to predict modes of behaviour based on this alone.
Let the arguing begin.
N.B. this is over-simplistic and was written hurridly between essays over a number of hours.