I think this is an 80s movie but could also be 90s.
The movie was about children (or children spirits) dressed in white robes, "trapped" in heaven and waiting to be chosen to go to earth i.e. be born. There was an old man also dressed in white, could have been god or a "father-time"-like figure, who would come to talk to the children and take them in a ship when the time was right.
Does anyone know the title of this movie so I can find it? Thank you!