First, let me say that the speculation about your great grandmother will not answer. If there were specific proof, that would be one thing, but a belief that a woman three generations back from you might have been Jewish, without any supporting evidence, is insufficient to establish anything. Without more definitive proof, you cannot claim Judaism through your maternal line.
That leaves your only possible claim to Jewish status as being through your paternal line. Before going any further, I should point out to you that this avenue is closed in the eyes of the Orthodox and Conservative movements, to my understanding. So you really need to ask yourself why you want to establish your Jewish status, and in whose eyes?
The Central Conference of American Rabbis declares that the child of one Jewish parent is under the presumption of Jewish descent. This presumption of the Jewish status of the offspring of any mixed marriage is to be established through appropriate and timely public and formal acts of identification with the Jewish faith and people. The performance of these mitzvot serves to commit those who participate in them, both parent and child, to Jewish life.
Depending on circumstances,1 mitzvot leading toward a positive and exclusive Jewish identity will include entry into the covenant, acquisition of a Hebrew name, Torah study, Bar/Bat Mitzvah, and Kabbalat Torah(Confirmation).2 For those beyond childhood claiming Jewish identity, other public acts or declarations may be added or substituted after consultation with their rabbi.
In order to overcome these problems as well as others, we now require "appropriate and timely public and formal acts..." The requirement has been worded to permit some flexibility for individual circumstances. With time and experience, custom will designate certain acts as appropriate and others not. It would be wrong, however, to set limits now at the beginning of the process.
We are aware that we have made more stringent requirements than our tradition. We believe that this will lead to a firmer commitment to Judaism on the part of these individuals and that it will enable them to become fully integrated into the Jewish community. We have taken this step for the following additional reasons:
1. We do not view birth as a determining factor in the religious identification of children of a mixed marriage.
2. We distinguish between descent and identification.
3. The mobility of American Jews has diminished the influence of the extended family upon such a child. This means that a significant informal bond with Judaism which played a role in the past does not exist for our generation.
4. Education has always been a strong factor in Jewish identity. In the recent past we could assume a minimal Jewish education for most children. In our time almost half the American Jewish community remains unaffiliated, and their children receive no Jewish education.
For those reasons the Central Conference of American Rabbis has declared: "The Central Conference of American Rabbis declares that the child of one Jewish parent is under the presumption of Jewish descent. This presumption of the Jewish status of the offspring of any mixed marriage is to be established through appropriate and timely public and formal acts of identification with the Jewish faith and people. The performance of these mitzvot serves to commit those who participate in them, both parents and child, to Jewish life.
“Depending on circumstances, mitzvot leading toward a positive and exclusive Jewish identity will include entry into the covenant, acquisition of a Hebrew name, Torah study, Bar/Bat Mitzvah, and Kabbalat Torah (Confirmation). For those beyond childhood claiming Jewish identity, other public acts or declarations may be added or substituted after consultation with their rabbi."
October 1983
It would seem that given your circumstances (a Jewish father, self-identification as a Jew) you would be accepted as Jewish within the Reform movement if you have also undertaken the signal acts noted in the last paragraph quoted.
If you have not engaged in these public acts, then it is far less clear. A related question to yours was submitted to this web site not long ago. It can be found on the website under the category of Miscellaneous topics in the subcategory of Status Issues at http://www.jewishvaluesonline.org/question.php?id=92&cprg=/search.php%3Fsubcatid%3D51. (I suggest that it may be instructive to read the answers provided as background to your question).
The facts in that earlier question differ from your situation in that there was no identified Jewish parent, nor were there timely public and formal acts of identification with the Jewish faith and people. You state that you have one specifically Jewish parent, and have apparently been raised to identify as a Jew, and to think of yourself as a Jew.
You do not state that you have made public or formal acts as a Jew, including undertaking formal religious education, Bar or Bat Mitzvah, Confirmation, or other signal acts. If these were not things you undertook, I would say, absent any other information, that you do not qualify to be considered Jewish under the stated criteria for the Reform movement, and you would be asked to undergo a formal conversion process.
The upshot of all this is that your status as a Jew may not be entirely certain, and open to doubt.
In matters of questionable status (instances of doubt), I have advised others in past that the easiest course seems to be to undergo the process of conversion. If you are technically Jewish, the conversion process will not change it, but rather affirm it; if you are technically not Jewish, conversion will change your status and provide you with firm proof of that status.
If you have been living Jewishly all your life, much of the educational and experiential component of the process will be easily accomplished, or may already be done, and you will be able to move through the process all that much more quickly, with your sponsoring rabbi. By undergoing a conversion, you will set all questions and doubts to rest. You can legitimately view this process as a positive adult choice to affirm and confirm your commitment to Judaism and the Jewish people, and to assert your identity and claim your heritage.
Good luck to you.
Rabbi Joe Blair
Answered by: Rabbi Joseph Blair