It would seem that there are certain strands of thought within many religions that are highly unsustainable, for the health of individuals as well society and the planet as a whole.
See this trailer for Holy Wars, as an illustration:
Certain beliefs, such as "my religion is the one right way and all others should live as I do," seem to presuppose perpetual conflict by design.
At the same time, religions are one of the most sustainable and self-perpetuating aspects of human culture. There is something deeply beneficial inherent in the stories about our purpose in the world that religion offers. Even atheists have a positive story about their meaning in the universe (Carl Sagan and Neil deGrasse Tyson are two people who have illustrated this beautifully).
So clearly stories are important to the sustainability and happiness of humans (and thus all other species living with us on the planet).
So maybe this is something we need to figure out...
How can today's existing religions shed the out-dated aspects of their beliefs (the unsustainable ones that perpetuate conflict) in a way that respects and celebrates cultural diversity?
Because more sameness isn't the answer. Cultural diversity is what gives human societies their beauty.
As Daniel Quinn has suggested, we need to replace the deadly memes with life-affirming memes. Instead of "there is one right way to live and my way is it," we need to spread a new idea: "There is no one right way to live."
Can you imagine how today's religions would be transformed by this one single change? How would they be different? What would remain the same? Could today's religions live on without the "one right way" meme, or is this meme like the foundation of a house of cards?
Lots to think about and discuss, for sure!