Shalom and thank you for turning to us. The question of conversion is one that should be dealt with by a special Beit Din (a Rabbinical court,) who specializes in this field of Jewish law. Most practicing community Rabbis do not specialize in it. Only a qualified Rabbinical court who specializes in this field can issue a Halachic decision regarding conversion, or the possibility of revoking a conversion.
To answer your question, in principle, once there has been Halachic conversion, the person remains Jewish according to Jewish law, even if he ceases practicing the precepts of the Torah, although this situation is not at all the ‘best case scenario ‘.
Let’s take a look at why this is. What IS a convert? It depends who you ask. A true Halachic convert is someone who has a deep desire to be a Jew. The story of each convert is unique but there is a unifying thread in all the stories, and that is that the decision to convert is made because of a desire beyond logic and intellect, a sense of identification with the Jewish people or a search for meaning… take for example the story of Ruth the Moabite princess. Her husband and parents in law were Jewish but her husband and father in law perished in the land of Moab, and thereafter her mother-in-law Naomi recommended that Ruth rejoin her people. Naomi was planning to return to the land of Israel which she had not wanted to leave in the first place. Ruth would have neither wealth nor honor by accompanying Naomi, but she was not looking for those things and she willingly relinquished a life of luxury as a princess in order to go with Naomi and live a life of morality. King David is descended from this brave and sincere woman.
Today also we see people from various walks of life such as an African prince, an American business woman, an Australian journalist, and so on and so forth, becoming Jewish because they truly BELIEVE in the Torah. According to certain Torah sources a convert possesses a Jewish soul from birth, but was born into a non-Jewish family and destined to find his/her path back to Judaism.
Let’s take a look at what it is not. A true convert is not someone who wanted to be accepted by the family or community of his or her friend and was never planning to keep the commandments of the Torah, and it is not someone who wanted to qualify for Israeli citizenship, or other reasons that do not have much to do with spiritual aspirations.
You use the term ‘kosher conversion’. There can be no other conversion. If it was not kosher, it was not a valid conversion according to Jewish law. When a non-Jew wishes to convert, the first thing Rabbis are supposed to do is discourage him or her and explain how burdensome it can be to keep all the many Mitzvot in all their details. The potential converts need to hear that even if they are seeking morality, there are the Seven Noahide Laws which are applicable to all mankind (and involve not stealing, killing, or blaspheming, among other things.) If after that the person is still serious about becoming a Jew, then they are unlikely to want to go back on that decision somewhere further down the line. Such a person, who has overcome obstacles and challenges in order to become a Jew, feels a sense of commitment to Jewish belief and identity.
There is a famous story about a Polish prince hundreds of years ago who converted to Judaism, despite the fact that a non-Jew at that time who was found to have converted would be punishable by death. This was an edict of the church, who ruled the people. Some converts managed to flee Poland or other countries which had similar laws, but the prince in question was found and executed, with the famous central prayer of Judaism, the ‘Shema Yisrael’ which denotes the unity of G-d, on his lips.
To sum up: a sincere convert is not likely to wish to revoke his/her decision, but may experience ups and downs in their Torah observance, which is normal. Judaism is not a club. In any event, each case is individual and must be brought before the appropriate forum – a qualified Rabbinical court.
Wishing you success in all your endeavors.
