Gettysburg address question. lincoln uses the images of birth and rebirth in this address. why?

The Gettysburg address was given by Abraham Lincoln following the battle of Gettysburg in the civil war. It is significant because after the battle of Gettysburg the south was in a losing position for the war and Lincoln knew he had to bring the country together once again. The address focuses on the country being one so the civil war could finally come to a peaceful end.

This is because of the rebirth of a new nation