I don't think it ever will. I just don't think you'll ever get people to give up religion. I think the atheists who think we're on track to become an atheist world one day are delusional. I think religion will not only be with us forever, but will be of the majority forever.
Atheist populations have steadily increased from virtually nothing to a frustratingly difficult to determine portion of the large but nebulous "non-religious" category - the #3 spot in the world behind Christians and Muslims. It might be hard to picture people giving up religion, but that's evidently what's going on in many parts of the world, particularly in Western countries
, and the data bears that out.
Here's what's been going on in the USA:
Of course, the USA is only around 5% of the world population, so don't cheer just yet. According to Pew Research Center
, the Unaffiliated category (which contains atheists, agnostics, non-religious, etc) is going to decline as a percentage of the world population by 2050. Unaffiliated numbers will still be on the in the West, but not nearly as a fast as religious, particularly Muslim, populations in developing countries. So any religious decline in the West is going to be more than offset by population booms in heavily religious developing countries.
The Gods may not be winning, but they're putting up a hell of a fight. But as countries gain achieve better standards of living and access to education, and more countries experience demographic transition (high birth rates and high death rates --> low birth rates and low death rates), irreligion might just win out over religion, albeit at least a couple centuries from now.