I took his comment to mean that Einstein didn't initially believe in it and it was an intellectual exercise at the time, not that he didn't believe in it after

I took his comment to mean that Einstein didn't initially believe in it and it was an intellectual exercise at the time, not that he didn't believe in it after evidence was built up. Kind of the flip side of the Michelson-Morley experiment where they set out to measure the properties of the ether and then tried to find what had gone wrong with their experimental method in that they couldn't detect the ether at all. Belief in the ether was wrong, yet they experimented on it anyway. Likewise, if a religious person decides to do experiments to find evidence the earth is not very old, and his experiment is done properly and fully documented, the experimental results he gets, whatever they are, can still be useful and valid. Maybe the results prove the earth is very old. Maybe they show that different methods of dating the same material give different results and that leads to a breakthrough in more accurate dating.