If you think about it with a slightly open mind those late additions reflect the need for xtian propagandists to fill in the blanks in the conversion of their godboy from a space cadet to an actual human.
Space cadet gods who live in outer space - which is what "paul" describes - and who then drop from the sky into Capernaum - which is what early xtian writers tell us that Marcion claimed - do not need birth or infancy stories. It is only when the process of euhemerization begins to take a legend and flesh it out with an actual biography that people would even begin to ask questions about a god's "birth" and childhood. And xtian propagandists were quick to fill the gaps in their history. Goebbels would have loved those guys.
Space cadet gods who live in outer space - which is what "paul" describes - and who then drop from the sky into Capernaum - which is what early xtian writers tell us that Marcion claimed - do not need birth or infancy stories. It is only when the process of euhemerization begins to take a legend and flesh it out with an actual biography that people would even begin to ask questions about a god's "birth" and childhood. And xtian propagandists were quick to fill the gaps in their history. Goebbels would have loved those guys.
Robert G. Ingersoll : “No man with a sense of humor ever founded a religion.”