The book “The Divine Code,” Volume I, gives the following instructions on this subject (p. 69-74), which are quoted here. The parts in square brackets [ ] are insertions for additional clarification:
“if a Gentile wants to do one of the other commandments from the Torah [beyond the 7 Noahide Commandments] in order to receive a practical benefit [for himself or for society] (but not as a direct commandment), [he should not be prevented] from doing so, even according to its correct laws [as they are to be fulfilled by a Jew] – for example, if he desires to tithe for charity from his money or produce, this is permitted…
However, if a Gentile observes any of the Jewish commandments from the Torah as a religious obligation (even if he does so from a desire to receive a spiritual reward), this is forbidden based on the prohibition of adding a commandment, and there is no spiritual reward to be derived from this.
A Gentile may not perform commandments that require the holiness of a Jew, such as writing a Torah scroll or the scrolls of phylacteries (tefillin) or a mezuzah. Gentiles are also forbidden to put on phylacteries at all, and they may not affix a mezuzah scroll on their door.
The general rule is that any Jewish commandment between man and his fellow man, or between man and G-d, which has a reason and a logical benefit for a person or society, is permitted for Gentiles to perform. But this does not apply for any commandment that does not have a logical, natural benefit, but is rather a sign for the Jews, such as ritual fringes (tzitzit), mezuzah scrolls, or phylacteries , or is a G-dly statute for the Jews without a reason or benefit understood to a person [as to how and why the ritual would bring any benefit]. A Gentile should be prevented from performing [this category of Jewish] commandments, and should be taught that it is improper for him to observe them.
The fact that male Gentiles are allowed have themselves circumcised as a spiritual observance, even though it is meant to be a sign in the flesh of a Jew, is not problematic, since many Gentiles practice circumcision for medical purposes, and not in order to add a commandment or a new religion. Furthermore, the Gentile descendants of Keturah [from her sons who were fatherd by Abraham] were commanded to observe circumcision, from which we can conclude that this commandment is not exclusively for the Jews.
Therefore, any Gentile male, who wishes to be circumcised in order to refine himself is permitted to do so. But if he is not [assumed within Torah Law to be] descended from a son of Abraham and Keturah, he should be informed that he has no obligation or commandment to do this, and that he should not do so for the sake of a commandment, but rather only to refine his personality and his body and its desires. [Arabic men are obligated by Torah to be circumcised, since the children of Ishmael were intermingled with the children of Keturah during the time of the Babylonian Empire.]
The above-mentioned rule applies only to Jewish commandments that are not duty-bound by logic (even if they have a logical reason) such as circumcision, or tithes [by which a person limits himself to give specifically 10% of his income to charity]. However, those that are duty-bound by logic, such as honoring one’s parents, and kindness and charity [in general], are obligated to be kept, because such is the correct way for a person to act, as befitting the “image of G-d” in which he was created. However, a Gentile may not keep them because it is a commandment from G-d, but rather because one is obligated to be a good, moral person.
Likewise, many prohibitions that are commanded upon Jews are obligations for Gentiles to observe based on logic, such as the prohibitions against hating others, taking revenge or bearing a grudge. A Gentile should observe these prohibitions out of human decency, and not as Divine commandments of their own.
This duty is an absolute obligation upon Gentiles, and they are liable to be punished for transgressing these obligations and for acting against moral and logical ways of practice, as the generation of the Flood was punished in the days of Noah.
Gentiles are obligated to give charity, and whether as an individual or a community, they are obligated to be concerned about help for the poor and needy, to help them appropriately in any way possible.Sodom and Gomorrah were destroyedsolely on account of their refusal to uphold and help the destitute, and their abolishing from their midst of any charity or help for the poor; because of this they were judged to deserve annihilation.
Gentiles are permitted to add any prohibitions in order to guard themselves against transgression, or to establish a correct and orderly society. This is desirous as a part of observing the obligations of the Noahide commandment to establish courts of law and develop proper societies in the world. Examples are Gentile societies that impose upon themselves restrictions against harassing women and children, and the punishments they set for transgressing such laws. The prohibition of adding a religion or a commandment does not apply to this, because it is part of keeping the Noahide obligations of establishing courts and laws, and proper societies in the world.
This only applies to restrictions Gentiles accept upon each other as communities, to avoid damages. But it is prohibited to add communal restrictions as if they were commanded by G-d (for example, if a Gentile community were to establish a law against eating meat from an unslaughtered animal carcass, as if it was a transgression like eating meat that was severed from a living mammal or bird), because this would be instituting a new religion.
However, if an individual wishes to accept a restriction in order to gain a practical personal benefit or to refine his personality, then he is not establishing the restriction as if it were a prohibition for him that is commanded from G-d, and it is permitted. Otherwise, it is prohibited.”
In summary, Gentiles should first and foremost understand and follow their Seven Noahide Commandments which G-d requires of them, for which the reward granted to the Torah faithful is a place in the World to Come. With this commitment, a Gentile should start keeping and learning about the Seven Noahide Commandments in the proper way, as they are explained within the Torah law received by Moses at Mt. Sinai. Under the guidance of an Orthodox Rabbi or mentor, this can certainly include the study of appropriate Chassidic discourses and teachings. A good additional observance to begin following is to give properly directed charity, and to give often [even daily, and even if it is only a small amount that is dropped into a charity can or box in one's home].
Although Gentiles are not to observe the restrictions or the distinctive rituals which are commanded to Jews for their Sabbath and religious festivals, there are a few of the Jewish festivals that have messages that are also applicable to observant Noahides, namely: Rosh HaShanah [the annual Day of Judgment for every person], Sukkot [the annual time of judgment for the rainfall that each nation will receive, which is also characterized by the themes of unity and joy], and Hanukkah [publicizing G-d's saving miracles to the public at large].
Source AskNoah International
Brought by Rabbi Moshe Perets
Rabbi Moshe Perets is the Founder and Executive Director of NoahideAcademy.org, the world’s largest Noahide informational website. He has established the Noahide Academy of Israel website under the non-profit organisation - אור לעמים - Light Unto the Nations since 2016. He accomplished his Rabbinical Studies at the Chabad Yeshiva of Brussels in 2011. He has a medical degree by the University of Louvain in Brussels as well a Masters in Biomedical Research by the Hebrew University of Jerusalem. He has for the past years focused on Psychotherapy and developed a new approach: Deep Soul Therapy. He is a spiritual mentor, teacher, coach, and healer who has helped facilitate profound shifts for hundreds of people around the globe. His teaching activities at the Noahide Academy allowed students from all over the world to live passionate, purposeful lives, connect more intimately with G-d, and reveal the hidden light and power of their souls. Rabbi Moshe Perets lives currently in Israel with his wife and 5 children.