A human birth is the only event in history when something eternal enters into time. This is because a human being has an eternal soul. This is because a human being is made in the image of God. We are not a mere mass of cells. It is not that our existence begins at birth, just our system of accounting time.
Our existence as a human being begins at conception. That person is alive with an eternal soul! This person then enters into what we count as time at the moment of birth. A human being, with an eternal soul, then begins life in time.
Marie-Celine Farver RN BSN IBCLC RLC (c) 2014