There’s been belief in, or at least implied reverence to, the supernatural since at least the time we harnessed fire. Something about being human either allows us to perceive and react to the supernatural, or to invent and believe it wholeheartedly. I think as long as our brains have wrinkles we’re going to have to deal with religious worship of the supernatural. Even if we also attend more faithfully to our worship of the scientific method.
Is any of that good dependent on religious belief? If the YMCA was completely secular, would that stop it from doing what it does? I don’t think so. Now, you could argue the same for the horrors of religion, but you’d need to find a different justification beyond just “I want to do good”.
So when Damon Fowler rejected the faith (not the morality that comes along with it, mind you, just the faith), how’d that social cohesion treat him? Religion is great for cohesion in the in-group. But it also solidifies that in-group against those who aren’t part of it. This is actually the downside to this proposal. In fact, when you say “society doesn’t have the same luxury”, I’d argue it doesn’t have the luxury to simply adopt religious mores without ditching the baggage. You don’t need religion for a societal religious basis. But in any successful religion, you’ll find this societal splitting. You’ll find people saying “those who don’t believe are evil”, “those who don’t believe are of the devil”, “we shouldn’t associate with those who don’t believe”. Hell, in some religions, it goes as far as “if you leave the religion, you will be shunned/attacked/killed”.
I can’t provide a real citation (how would you even study that), but I can offer countless cases where a religious family rejected their children or relatives or neighbors because they did not hold the same faith, or because they were gay, or because of similarly trivial things. And I can provide religious leaders who preach separation and isolationism, who claim that the “other” is evil, corrupt, and dangerous. This is the sort of thing that’s easy to miss when you’re not the target of it.
In any case, I categorically reject the claim that religion increases social cohesion. It’s completely baseless and runs directly contrary to everything I’ve seen in my own experience.
The Abrahamic derivations, at least, eat away at the concept of free will and accountability, and damn humanity to a stasis in which oppression squashes free and natural thought at every turn. If you don’t obey the stone-age doctrines to the letter in the 80 or so years you walk this earth, your loving creator will give you an eternity of suffering–but go ahead and exercise your free will. It’s blackmail at its very heart and enriches the leadership of the organization at the cost of those it claims to lead. If manipulating others into giving their lives and aspirations for your own gain isn’t evil I don’t know what is. Giving a sufferer a lie and some directions might make them feel better, but it is nevertheless the theft of a soul.
Other religions–of India, of Japan, of Africa, of Australia, of Polynesia, or pre-Columbian N/S America I know too little about to comment on.
…And yet, someone did propose quantum mechanics. They weren’t carted away; the people who advanced the theory got quite a few Nobels for it.
Maybe in a few millennia, maybe, but 100 years? I can’t possibly see it happening.
It will depend upon the emergence of widespread biological engineering of higher intelligence into the species. Until that technology is commonplace, religion will be alive and well. 100 years is probably a realistic timeframe.