It's simple really. God (there are many - each civilisation creates its own god, of course) was created by man in order to provide a believable explanation for everything that was inexplicable.
As the centuries rolled by, scientific explanations for the inexplicable have appeared. As more and more things are scientifically explained, the need for a god becomes less important.
One day then, logically, there will be no need for a god.
Of course, we atheists don't need one anyway. We just accept that some phenomena still remain to be explained.
Would you be an atheist if you were born in Pakistan to pakistani muslim parents??
Nope, he would not have a choice, if he does not accept Islam voluntarily, it will be forced down his throat, if he still declines, then, he would be threatened, beaten by parents, and later on in his life he could well be killed. Islam is forced on them by the parents, and that is a fact, from day one. Not only in Pakistan, but throughout the world. give and take an exception here and there, some very moderate muslims may not care if their child does not follow Islam. But they definitely won't let him take up any other religion.
Also Children born under two different religious partners, if the mother does not convert to Islam before the child is born, the child would be called illegitimate or there is a muslim word called haram, which is opposite of halal.