Ultimately, all is understood: fear G-d and observe
His commandments, for this is the completion of man.
Kohelet (Ecclesiastes) 12:13
With respect G-d's commandments, all of humanity is divided into two general classifications: the Children of Israel and the Children of Noah.
The Children of Israel are the Jews, the descendants of the Patriarch Jacob. They are commanded to fulfill the 613 commandments of the Torah.
The Children of Noah are the Gentiles, comprising the seventy nations of the world. They are commanded concerning the Seven Universal Laws, also known as the Seven Laws of the Children of Noah or the Seven Noahide Laws.
These Seven Universal Laws pertain to:
Men and women are equal in their responsibility to observe the Seven Universal Laws.
When a Gentile resolves to fulfill the Seven Universal Laws, his or her soul is elevated. This person becomes one of the "Chasidei Umot Haolam" (Pious Ones of the Nations) and receives a share of the World to Come. The Torah calls one who accepts the yoke of fulfilling the Seven Universal Laws a "Ger Toshav" (a Proselyte of the Gate).
This person is permitted to live in the land of Israel and to enter to the Holy Temple in Jerusalem and to offer sacrifices to the G-d of Israel.
If a Gentile wishes to accept the full responsibility of the Torah and the 613 commandments, he or she can convert and become a Jew in every respect.
It is a principle of Judaism, however, not to seek converts and one who requests conversion is generally discouraged. Should the person persist in his or her desire to convert, counsel should be taken only with an Orthodox Rabbi or Torah Scholar, for conversion not in accord with Halacha - Torah Law - is no conversion at all, and conversion bestowed by "rabbis" who themselves do not follow the Laws of the Torah are null and void, neither recognized in heaven nor by any G-d-fearing Jew.
It is incorrect to think that since the Children of Israel have 613 commandments and the Children of Noah have seven commandments, that the ratio of spiritual worth is proportionally 613 to seven.
The Seven Universal Laws are general commandments, each containing many parts and details, whereas the 613 Commandments of the Torah are specific, each relating to one basic detail of the Divine Law. Therefore, the numerical disparity in no way reflects the relative spiritual worth of the two systems of commandments.
Besides the Seven Universal Laws, the Children of Noah have traditionally taken it upon themselves to fulfill the commandment of honoring mother and father, and the commandment of giving charity.
If a Noahide who follows the Seven Universal Laws gives charity, the Israelites accept it from him, and give it to the poor of Israel since through the merit of giving charity to the poor among the Jewish people one is given life by G-d and saved from death. But a Gentile who does not accept the yoke of the Seven Noahide Laws and gives charity is not permitted to give it to the needy of Israel. His charity may be given only to poor Gentiles.
By observing the Seven Universal Laws, mankind is given the means by which it can perfect itself.
The individual, through these laws, has the power to refine his
essential being, and can reach higher and higher without limit.
For it is written,
I call heaven and earth to bear witness, that
any individual, man or woman, Jew or Gentile, freeman or slave,
can have the Holy Spirit bestowed upon him. It all depends on his
(Shaare Tzedek 60a, 60b)
The Jew has a crucial role to play in this. He cannot be a bystander, remaining aloof from the world's conduct. Every Jew has the obligation to ensure that all the people of the world observe the Seven Noachide Laws.
It is through the observance of the Seven Noachide Laws that the entire world becomes a decent, productive place, a fitting receptacle for the Divine.
The Rambam explicitly rules (Code, Kings 8:10):
commanded from the mouth of G-d to convince all the inhabitants of the
world to observe the commandments given to the Children of Noach.
It is the Jew's duty to see to it that all peoples lead the righteous and decent life which comes from compliance with the Seven Noachide Laws. Not only is it a Jew's duty because he has been so commanded by G-d, but it is also to his own benefit.