We need to start here.
Jeremiah 1:5 (New International Version)5 “Before I formed you in the womb I knew[a] you,
before you were born I set you apart;
I appointed you as a prophet to the nations.”
This passage means all of us were with God before we were known by our parents. Our Spirits belong to God not to us.
We are born with the memory of where we have come from ( the spirit realm or Heaven ). Over time most of us lose these memories and as a result our sense of reality changes. We no longer see angels, demons, and spirits.
Later at the end of our lives, as we approach death we will once again see into the realm of spirits. Of course this will be the case only if the death is a natural non sudden event. Many times the dying will report seeing someone who had long ago passed away. They may see things that to us don't make sense. But rest assured what they see is there and very real.
Back to babies for a moment. I believe the babbling we hear from babies is in fact a language. A language long forgotten by us but fluently spoken by our new arrivals. The language is Angelic and is spoken in the spirit realm. So the next time you see a baby or a toddler speaking to something you cant see, praise God--your baby is!
God bless you all!