Noahide Oath before a Rabbinical Court
Rabbi Yoel Schwartz (Jerusalem Court for Bnei Noah)
A person who wants to do only those good deeds that he feels impelled to perform without being ordered to do so stresses his own importance. He thinks that he is the focus of everything. But when a person decides to carry out the Mitzvot because he has been ordered to by G-d, then he feels the importance of the G-d that orders. It is only then that he manages to discover and find all his hidden powers in order to carry out these mitzvot. These hidden powers cannot be tapped to their utmost if a person carries out the mitzvot simply because he has the sudden urge or mood to do so. This decision is strengthened even more when the person announces it before three learned and wise Jews. This acts transforms the person into a Ger Toshav. Even today, when, since all of the Israelites have not yet returned to their land, the laws concerning a Ger Toshav are not applicable – in reference to the special privileges which would otherwise apply to a non-Jew who has made such a declaration – such a declaration made before three observant Jews nevertheless still enhances the status of the non-Jew.
This declaration should include: belief in the principles of the existence of the one true G-d, who is everlasting, the Creator of all things, guides all of his creations, is the One that gave the Torah on Sinai for all of humanity, and oversees all the actions of the human beings to reward and punish them for their deeds. Then the person should state that he is willing to fulfill the seven mitzvot that were given to Noah. (There are those who believe that this announcement should be accompanied by submersing in a pool of at least 660 liters of water, like the sea, spring or a man-made pool built in the earth. However we know of no basis for this view.)
The reason for the submersion is simple purification. It is desirable for anyone who enters the synagogue to be in a state of ritual purity, if a Ger Toshav really does intend to show his/her belief in Rabbis then taking a mikvah is a good sign of this.