While the Christian Church is wilting, people need something to believe in. You will get more Islam/Buddism/New Age spiritualist etc etc etc conversions. If you convince everyone Jesus isn't the answer, then they cling on to the next big thing.
But besides all that, atheist societies have low birth rates and they get replaced by religious ones. Besides the gays not reproducing, the partying/career crew not reproducing, you also have the issue of marriage for life no longer being trendy.
For a start, men are afraid of getting a woman pregnant because they just expect to be taken for a ride half the time and have to pay out half their wages to a woman who hates them for the next 18 years. Also a mother who finds a new man who is agreeable to children and doesn't have more children with him stops him from having kids with someone else.
In other words religion will rule again in the West, but it perhaps won't be Christianity. Islam is the likely contender, but if that's not it, something else will become widely established. I have heard half the world's population are projected to be Muslim by 2100. They are up to 25% already and rapidly increasing %.
the marvels of the world can now almost all be explained by Science
A religion that doesn't contradict science and promises an afterlife and a reason for everything is better than just science for most.
Despite Dawkins arguing religion is harmful from a natural selection point of view, atheism is a complete evolutionary dead end due to birth rates of atheists compared to theists.