It would help the discussion to understand what, if anything, babies believe in. Or what we babies accepted as reality.
Interesting, to me, that babies are presented as a 'them' category, when everyone reading this was at one time, 'them.' Seems more appropriate to discuss it as an 'us' proposition. What as a baby did you believe in?
I personally don't recall much from that time, but really do think I saw my parents as highly influential to my being, and not far removed from how some people currently understand the term 'god.'
But I also realize that as a baby, I wasn't aware that I was a baby, nor that I was born, nor that beliefs exist. Without any (intellectual) beliefs, but existing as a person that accepts a reality, I wonder if us adults can actually comprehend that type of existence. For all we know, that is knowledge. We label it as ignorance, but participate on threads 80 pages deep debating the minutiae about the very idea of beliefs. Thinking it will lead to knowledge on beliefs, or lack thereof. Perhaps we are still in our infancy?