Why the virgin birth; was Mary of Davidic line; did her sinlessness matter?
Robert Sungenis answers that Mary descended directly from Abraham and David, fulfilling the promise made to David's line, and was the virgin prophesied in Isaiah who would bear Emmanuel. He holds that her virginity prevented any transmission of sin through human seed and her immaculate conception ensured the humanity of Christ was pure, which is why he treats both her perpetual virginity and her immaculate conception as necessary truths.
Why the virgin birth; was Mary of Davidic line; did her sinlessness matter?
Answer
Mary descended directly from Abraham and David, fulfilling the promise made to David’s line. She was the virgin prophesied in Isaiah who would bear Emmanuel, “God with us.” She was not only a virgin but immaculate, without original or actual sin. Her virginity prevented any transmission of sin through human seed. Her sinlessness ensured the humanity of Christ was pure. That is why both her perpetual virginity and her immaculate conception are necessary truths.