Was Mary really Jesus' Mother? This may seem like a stupid question, until you realize that this is really being debated today by sincere, God-fearing Christians. To make things clearer, let me be a bit more explicit about what I'm asking: Was Mary Jesus' biological mother? Did Jesus have any of Mary's genes in him? Was he flesh of her flesh? Or did God merely plant a perfect embryo inside of Mary's womb?
I think that the scriptures answer this question, not directly, but quite conclusively. Let me show you what I mean; then you can judge for yourself.
In Acts 2 we have the record of the first sermon preached in the history of the Church, on the Day of Pentecost. In the course of this sermon, Peter makes an important statement about David.
Acts 2:29-32.
29 Men [and] brethren, let me freely speak unto you of the patriarch David, that he is both dead and buried, and his sepulchre is with us unto this day.
30 Therefore being a prophet, and knowing that God had sworn with an oath to him, that of the fruit of his loins, according to the flesh, he would raise up Christ to sit on his throne;
31 He seeing this before spake of the resurrection of Christ, that his soul was not left in hell, neither his flesh did see corruption.
32 This Jesus hath God raised up, whereof we all are witnesses.
The key verse for our purposes is verse 30. According to Peter, speaking by the Spirit of God, God swore to David by an oath that He would raise up the Messiah to sit on David's throne FROM THE FRUIT OF DAVID'S LOINS according to the flesh. He did not merely promise that the Messiah would be born in David's family; instead, He swore that the Messiah would be a genetic descendent of David.
Now while Joseph was a genetic descendent of David, the scripture makes it quite clear that he was not Jesus's natural father. Thus, the fulfillment of God's oath in this matter depends on Mary. If she was truly Jesus' mother in a natural and genetic sense, then this oath has been fulfilled. If she was not, then God broke His word, given by an oath, to David.
For me that pretty much settles the matter. While the scripture makes it quite clear that Jesus was not literally the son of Joseph, it makes no such distinction about Mary. Jesus always referred to her as his mother, with no qualifications. The scripture does likewise. And, as we've seen, the integrity of God's Word requires that this be the case.