Mary
Luke 1:26-38
Hail, full of grace, the Lord is with thee: blessed art thou among women... Behold the handmaid of the Lord; be it done to me according to thy word.
Context of the passage
The Annunciation, when the Archangel Gabriel announces to Mary that she will conceive the Son of God, and she freely consents.
Catholic reading
The angelic greeting 'full of grace' (kecharitomene), a perfect passive participle indicating a completed and permanent state of grace, is the biblical seed of the doctrine of Mary's Immaculate Conception and unique holiness.
Common objection
'Full of grace' is simply a title of divine favor, not proof of sinlessness or a special conception.
Response
The Greek grammatical form used for no one else in the New Testament suggests an already-perfected, singular grace preceding this moment, consistent with the Church's ancient reflection that God prepared Mary as a fitting vessel for the Incarnate Word.