This is one of my favorite stories about my family, and we have a lot of good stories. But that cat (Bart was his name) was really into taking care of me and my mom. And I'm not telling this story just for kicks or for the joke; there is a point here. If you can get altruism of a creature that doesn't even have language, then you can definitely be good without god.
One of my basic rebuttals against theists is that we do not need stories to want to be good. Empathy, altruism, generosity, care-taking etc. are all baked in. And not just baked into our biology, but into the biology of the "lower" animals; the ones that demonstrably do not have language.
I think it is important for us to consider that our animalness isn't all bad. Our evolutionary history makes us what we are. And while we are complex animal, with a wide and troubling range of behavior, there are noble qualities that are our heritage, and not a gift from on high.
The religions have demonized our "animal nature" for a long time and I think it is a kind of self hate. The line in the sand is not between emotional and rational. It is not between the spiritual and the flesh. The saved and the fallen.
The line in the sand is between what harms and what helps. And there are helpful things that are of the flesh, that are of the fallen and of the emotional. And I think we would do well to reconsider how we divide what we are proud of and what we are ashamed of.