“But when the time had fully come, God sent forth his Son, born of woman, born under the law, to redeem those who were under the law, so that we might receive adoption as sons.” (Gal 4:4–5)
The angel Gabriel was sent by God to the Virgin Mary in Nazareth, and this was a decisive moment in the history of salvation. In His love, God chose from among His people the person to whom He would entrust His own Son. She was a woman who, as we know with certainty thanks to the dogma of the Catholic Church, was preserved by God from original sin.