Because rabbis in the other movements do not require that converts make this commitment, Orthodox authorities do not generally accept as valid conversions performed outside the Orthodox community.
But, those born Jewish do not lose that status because they cease to be observant Jews, even if they adopt the practices of another religion.
According to halakha, to determine a person's Jewish status (Hebrew: yuhasin) one needs to consider the status of both parents.
For those beyond childhood claiming Jewish identity, other public acts or declarations may be added or substituted after consultation with their rabbi." Waiving the need for formal conversion for anyone with at least one Jewish parent who has made affirmative acts of Jewish identity was a departure from the traditional position requiring formal conversion to Judaism for children without a Jewish mother.
The CCAR's 1983 resolution has had a mixed reception in Reform Jewish communities outside of the United States.
However, there are differences in interpretations when it comes to non-Orthodox Jewish denominations in the application of this definition, including According to the Mishnah, the first written source for halakha, the status of the offspring of mixed marriages was determined matrilineally. He brings two likely explanations for the change in Mishnaic times: first, the Mishnah may have been applying the same logic to mixed marriages as it had applied to other mixtures (kilayim).
Thus, a mixed marriage is forbidden as is the union of a horse and a donkey, and in both unions the offspring are judged matrilineally.If both parents are Jewish, their child will also be considered Jewish, and the child takes the status of the father (e.g., as a kohen).If either parent is subject to a genealogical disability (e.g., is a mamzer) then the child is also subject to that disability.According to Jewish law, a person is only considered Jewish if their mother is Jewish, or they underwent a proper conversion.Exceptions are made within Reform Judaism and Reconstructionist Judaism, which accept patrilineal descent.Not all conversions are recognised by all varieties of Judaism.