Writings indicate that mothers determine Jewish status

Dear Rabbi Fried,
I have a friend who is presently a practicing Methodist minister. He asked me to find out for him why the religious status of a Jew is determined by the mother, not the father. Could you please help me with this?
Marshall L.
Dear Marshall,
Let us analyze the source of matrilineal descent in Judaism.
Although the determination of which of the 12 tribes one would belong to depends upon the father, the essential Jewish status, itself, depends upon the mother (Talmud Tractate Kiddushin 88b).
Before the transmission of Torah at Sinai, the definition of belonging to the Abrahamic lineage was patrilineal, as we find that many of the sons of Jacob married outside the family. The principle of matrilineal descent was introduced at Sinai, when the Abrahamic nation technically became Jewish.
Furthermore, the Torah states: “You shall not intermarry with them; you shall not give your daughter to his son, and you shall not take his daughter for your son, for he will cause your child to turn away from Me and they will worship the gods of others…” (Deuteronomy 7:3). The question is, why is the Torah only concerned that “he,” the son, will sway your grandchildren away from God, but not that “she,” the non-Jewish mother, will do the same?
The Talmud infers from this verse that only the non-Jewish father could sway your Jewish grandchildren away from Judaism, as he is Jewish if his mother is Jewish. But, if the mother is not Jewish, then it is too late to worry. The grandchildren will be swayed away as they are not Jewish to begin with, as the Jewish status depends upon the mother, not the father.
We were not given an explanation in the Torah, explicitly, why God established this definition of a Jew. I understand it as follows. We are, as humans, not just bodies, but bodies and souls. We received our spiritual handbook at Mount Sinai. The Kabbalistic writings tell us that the Jews at Sinai were endowed with unique, expanded souls, as a receptacle for all the amazing spiritual energy about to be unleashed. We continue to receive those expanded souls throughout the generations, to continue to hold all the energy of Sinai, and to emit that energy to illuminate the world as a “light among the nations.”
The Talmud says that the soul is endowed in the fetus on the 40th day from conception, while in the mother’s womb. According to this Talmudic teaching, where the baby was on Day 40, i.e., whose womb he or she is in, is the key determination as to which type of soul they will receive, a Gentile soul, or a Jewish one. (Location, location, location!)
Hence, the Judaism of the child depends upon the mother, as the fetus rests in the mother’s womb. Although there’s much more to discuss on this matter, those are a few points in a nutshell.