I never said any such thing about obliteration. The Church is the People of God. Israel is the People of God.
If A = C and B = C, then A = B.
Regards
Sorry. It doesn't work that way. Read Romans 9-12 for that matter. It explains the whole thing.
Incidentally, what about: Matthew 13:55
"Isn't this the carpenter's son? Isn't his mother's name Mary, and aren't his brothers James, Joseph, Simon and Judas?
Mark 6:3
"Where did this man get these things?" they asked. "What's this wisdom that has been given him, that he even does miracles! Isn't this the carpenter? Isn't this Mary's son and the brother of James, Joseph, Judas and Simon? Aren't his sisters here with us?" And they took offense at him.
Mark 15:40
Some women were watching from a distance. Among them were Mary Magdalene, Mary the mother of James the younger and of Joses, and Salome.
You will likely say, these are Joseph's children or cousins. Scripture doesn't say that. Adelphos is usually translated brothers.
Acts 1:14
They all joined together constantly in prayer, along with the women and Mary the mother of Jesus, and with his brothers.
But lets' look at what Christ Himself said...
31Then Jesus' mother and brothers arrived. Standing outside, they sent someone in to call him. 32A crowd was sitting around him, and they told him, "Your mother and brothers are outside looking for you."
33"Who are my mother and my brothers?" he asked.
34Then he looked at those seated in a circle around him and said, "Here are my mother and my brothers! 35Whoever does God's will is my brother and sister and mother."
Does it REALLY make sense that Jesus would have been saying "here are my mother and my cousins?" Now such doesn't eliminate Joseph's unmentioned earlier wife from the equation - but contextually it seems that Jesus is recognizing these people as His Mother Brothers and Sisters.
Firstborn again lends biblical support that they are children of Mary.