but a house built on a weak foundation can fall apart much more easily than one built on a solid one

I'd say it's pretty bleedin' obvious that the house with the strongest foundation is the world's oldest living cultural group: Aboriginal Australians. Obviously, belief in the Rainbow Serpent has greatly benefitted their ancient nations. They preserved knowledge of the sea level rise at the end of the ice age through 10,000 years, that's the best history-keeping in the world. I'd say Aboriginal religions are carefully calibrated machines of political technology, creating good societies through social engineering.

The results speak for themselves: Believing in the Rainbow Serpent is the right thing to do, because it makes the world a better place. So I believe.