I don't think belief in an undetectable meta mind is needed to acknowledge that what we do matters.
Ideas do measurably travel. Works of writing and art, leave ripples across time, and even interact with eachhother.
We also have decent data that even small acts of kindness and decency can have compounding long term effects.
I'm sure my name won't go down in history, and I don't want to get bent out of shape the way I have seen people who care about being remembered get bent.
Instead, I choose to have faith that (results of) my acts of kindness will still be bouncing around out there, paying themselves forward, to bless even my own great-grandchildren, and the great-grandchildren of others. There's so many people I can never repay for their kindnesses, but hopefully my own choices will bless people they cared about someday.
I think the patron saints of this odd belief of mine are Fred Rogers and Bob Ross. I defy anyone to seriously believe that the good those put into the world will fully stop propagating when they are forgotten. So many people are better people today because of their choices. Their "spirit" will continue to pay forward under other names.