It seems to me that babies are not born as believers, nor as disbelievers. And they are not even born as agnostics. As born, they lack the concepts for any of those positions.
I wish we didn’t spend so much effort on these turf battles. But maybe we could all try to avoid conscripting babies to our teams.
Should we spin this off into a new category? Are Atheists Babies? Hahaha. Just kidding. 
There was a study a few years back out of Stanford and UI-Champaign/Urbana I believe, that showed that babies have an innate sense of good vs. evil. It’s not the same as God, but it is interesting. I can’t find the exact study, but this article references some:
I don’t know why, but for some reasons, scientific study of babies, intrusive or not, makes me really uncomfortable.
It was interesting how it was done and it was not intrusive at all… it was done with colored puppets where one puppet took from the other. Then they watched to see which puppet the babies gravitated toward to play with. To ensure that it was not a puppet-color-related issue, they reversed the roles and found that the babies could empathize with the puppet from which things were taken and did not like the other.
Reminds me of a TED talk I saw once about a study showing that babies can use inference to the best explanation: https://www.ted.com/talks/laura_schulz_the_surprisingly_logical_minds_of_babies
Nice!! Any TED talks on when this ability is lost?? Surely, shortly thereafter… 
Sometime during puberty.
Hahaha! For sure!!
There are some very interesting and clever experiments done in Developmental Psychology, showing how babies gain certain capability at certain ages (Object permanence, Theory of Mind, etc.).