Jewish by mother or father?

[White Israelite]

Defining who is a Jew is done by the mother, if the mothers Jewish and the fathers no Jewish, the child is still Jewish because the mother is.

But if the mother is a Goyium and the father is Jewish, the child is not Jewish unless the mother converts.

Why is this?

Wasn't it originally the child was Jewish if the father was Jewish? Why did this change if so? Does G-ds word change?

[jdl4ever]

It didn't change.  The Torah over there was talking about tribal lineage.  Tribal lineage goes after the father.  So if your mother was from the tribe of Benyamin and your father was from the tribe of Judea, you'd be considered from the tribe of Judea.  Jewish lineage goes after the mother though. 

[Wayne Jude]

OK

[jdl4ever]

They'd be Jewish but without a tribe.  There was a separate area of the Land of Israel that was reserved for converts who by definition don't belong to a tribe.   The rest of Israel was divided into tribal areas.  At least that's what I learned.

[White Israelite]

They'd be Jewish but without a tribe.  There was a separate area of the Land of Israel that was reserved for converts who by definition don't belong to a tribe.   The rest of Israel was divided into tribal areas.  At least that's what I learned.

What about those with a Goy mother and a Jewish father?

[White Israelite]

If the child has a Gentile mother and a Jewish father, then the child is not Jewish.  And this can even be seen from the Tanach in the time of Ezra when they encouraged the Jewish males to get rid of their non-Jewish wives and children after they returned from the first exile:

Ezra 10:

1. And when Ezra prayed and confessed, weeping and prostrating himself before the House, a very large assemblage of Israel, men, women, and children, gathered to him, for the people wept with much weeping.
2. And Shechaniah, the son of Jehiel, of the sons of Elam, raised his voice and said to Ezra, "We have betrayed our G-d, and we have taken in foreign wives of the peoples of the land, but now there is hope for Israel concerning this.
3. And now, let us make a covenant with our G-d to cast out all the wives and their offspring, by the counsel of the Lord and those who hasten to [perform] the commandment of our G-d, and according to the Law it shall be done.
4. Rise, for the matter is incumbent upon you, and we are with you; be strong and do!"
5. Then Ezra rose and adjured the chiefs of the priests, the Levites, and all Israel to do according to this matter, and they swore.
6. Then Ezra rose from before the House of G-d, and he went to the chamber of Jehohanan the son of Eliashib. [When] he went there, he neither ate bread nor drank water, because he was mourning over the treachery of the community of the exiles.
7. And they issued a proclamation in Judea and Jerusalem to all the people of the community of the exiles to assemble to Jerusalem.
8. And whoever does not come by three days according to the counsel of the chiefs and the elders all his property shall be confiscated, and he shall be separated from the congregation of the exile.
9. And all the people of Judah and Benjamin assembled to Jerusalem by three days; that is the ninth month, on the twentieth of the month, and all the people stayed in the broad plaza of the House of G-d, quaking over the matter and because of the rains.
10. And Ezra the priest arose and said to them, "You have dealt treacherously, and you have taken in foreign wives to add to Israel's guilt.
11. And now, confess to the Lord, the G-d of your forefathers, and do His will, and separate from the peoples of the land and from the foreign wives."
12. Then the entire congregation replied and said in a loud voice: "Yes! We must do as you say!
13. But the people are many, and it is the rainy season, and there is no strength to remain outside, and the work is not for one day and not for two, for we have sinned very much in this matter.
14. Let our chiefs remain now with the entire congregation, and whoever is in our cities who took in foreign wives shall come at appointed times and with them the elders of every city and its judges, until we avert the burning anger of our G-d from us until this matter [is concluded]."
15. Only Jonathan, the son of Asahel, and Jahzeiah, the son of Tikvah, stood up against this, and Meshullam and Shabbathai the Levite supported them.
16. The people of the exile did so. Ezra the priest [and certain] men, heads of the fathers' houses after the house of their fathers, separated themselves, all of them [known] by name, and they convened on the first day of the tenth month to investigate the matter.
17. And they completed everything concerning the men who had brought in foreign women, until the first day of the first month.
18. And it was found of the sons of the priests who brought in foreign women, of the sons of Jeshua, the son of Jozadak, and his brothers: Maaseiah, Eliezer, Jarib, and Gedaliah.
19. And they advised them to cast out their wives, and the guilty ones [to bring] a ram for their guilt.
20. And of the sons of Immer: Hanani and Zebadiah.
21. And of the sons of Harim: Maasiah, Elijah, Shemaiah, Jehiel, and Uzziah.
22. And of the sons of Pashhur: Elioenai, Maaseiah, Ishmael, Nathaniel, Jozabad, and Elasah.
23. And of the Levites: Jozabad, Shimei, and Kelajah-he is Kelita-Pethahiah, Judah, and Eliezer.
24. And of the singers: Eliashib; and of the gatekeepers: Shallum, Telem, and Uri.
25. And of Israel, of the sons of Parosh: Ramiah, Izziah, Malchijah, Mijamin, Eleazar, Malchijah, and Benaiah.
26. And of the sons of Elam: Mattaniah, Zechariah, Jehiel, Abdi, Jeremoth, and Elijah.
27. And of the sons of Zattu: Elioenai, Eliashib, Mattaniah, Jeremoth, Zabad, and Aziza.
28. And of the sons of Bebai: Jehohanan, Hananiah, Zabbai, [and] Athlai.
29. And of the sons of Bani: Meshullam, Malluch, Adaiah, Jashub, Sheal, and Ramoth.
30. And of the sons of Pahath-Moab: Adna and Chelal; Benaiah, Maaseiah, Mattaniah, Bezalel, Binnui, and Manasseh.
31. And of the sons of Harim: Eliezer, Ishijah, Malchijah, Shemaiah, Simeon.
32. Benjamin, Malluch, [and] Shemariah.
33. Of the sons of Hashum: Mattenai, Mattattah, Zabad, Eliphelet, Jeremai, Manasseh, [and] Shimei.
34. Of the sons of Bani: Maadai, Amram, and Uel.
35. Benaiah, Bedeiah, Cheluhu.
36. Vaniah, Meremoth, Elyashib.
37. Mattaniah, Mattenai, and Jaasai.
38. Bani, Binnui, Shimei.
39. Shelemiah, Nathan, Adaiah.
40. Machnadebai, Shashai, Sharai.
41. Azarel, Shelemiah, Shemariah.
42. Shallum, Amariah, and Joseph.
43. Of the sons of Nebo: Jeiel, Mattithiah, Zabad, Zebina, Jaddai, Joel, and Banaiah.
44. All these had taken foreign wives, and some of them had wives by whom they had children.

Get rid of their children? That sounds a bit cruel.

[White Israelite]

I was debating the issue and someone was mentioning

David came from Ruth and that would cut him out being king and an Israelite. Is this true?

[newman]

Defining who is a Jew is done by the mother, if the mothers Jewish and the fathers no Jewish, the child is still Jewish because the mother is.

But if the mother is a Goyium and the father is Jewish, the child is not Jewish unless the mother converts.

Why is this?

Wasn't it originally the child was Jewish if the father was Jewish? Why did this change if so? Does G-ds word change?

Why?.......

Because Torah (the word of G_d) says so.

There was no "change". One's tribe (Benjamin, Cohen, Levi etc) is determined by ones father. One's Jewishness is determined by the mother.