Why be a Noachide?
First, you already are a Noachide. Noachide simply means you are bne'i Noach – a child (descendant) of Noah. As the story goes, Noah and his family were the only human beings God saved from the flood which he used to destroy the creatures and people of the earth.
Therefore from this story we learn that every human being is a descendant of Noah. And, if you don't believe in the story of Adam and Eve, or Noah and the Flood, it can be pointed out we are all related to each other anyways by our Most Recent Common Ancestor.
However, what is really meant by the term Noachide (versus son-of-Noah, ben-Noach or bne'i Noach) is someone who chooses to identify as a Noachide versus some other religion such as Buddhist, Muslim, Christian or Jewish. Therefore it is important to be able to answer the question “Why Noachide?” as it is asked by people of other faiths.
First, as Noachides we claim Ecumenical Authority. We make this claim based on Sola Scriptura, backed by the Jewish claim of National Revelation – in short, we pre-suppose that the bible is the word of God.
Then, based on the bible, we offer the following biblical proofs;
Genesis 6:9 and 7:1 state that the man Noah was righteous and blameless in God's eyes. Some people may dispute the validity of this based on the doctrine of Original Sin. Therefore we ask, Was Noah Righteous and through a complete discussion of this point we understand for whatever reason and by whatever means, for at least that moment Noah was righteous, and we move on to our next point.
Next we present that God made a covenant with Noah which was to be perpetual forever, and this covenant has never been repealed anywhere in the bible. Indeed God states in more than one place the covenant would last until the end of the earth.
God's obligation is that so long as Noah and all his descendants kept the commandments of that covenant, God would never again destroy the earth nor destroy every living creature. The earth would endure, as written in and around Genesis 8:22.
Noah's obligation under the covenant was not merely to avoid doing certain bad things (for example, do not murder; do not steal) but also to preserve his righteousness among his descendants for all time. In Genesis 9:3 God makes reference to earlier Adam-ic commandments when speaking with Noah. “…and just as I gave you the green plants, I give you everything.” implying that Noah's righteousness was connected to his keeping of the older, Adam-ic commandments such as “be fruitful and multiply”. This then will include the specific order to turn away from, and master over his sinful nature, doing only good (Genesis 4:7).
Further, in Genesis 9:6 God states
“Whoever sheds the blood of a human,
by a human shall that person’s blood be shed;
for in his own image
God made humankind.”
This “by a human” means there must be someone available to enforce the command here given by God; i.e. Noah was commanded to act in order to enforce God's will in this matter.
What's more, God gives his rationale for this commandment; we are to take action and enforce this (“To establish courts of justice”) specifically because we were created in God's image. That means on this matter we are to act as the one giving commandments and enforcing the law, for the purpose of fulfilling God's will. This commandment is noted as being one of the very few 'active' commandments given to Noah.
If you are having difficulty understanding this point allow me to point out that by establishing a central authority for Noachide concerns alleviates all problems of jurisdiction; for example in the story of Pinchas his act of killing people was regarded as righteousness because the killing was done in concordance with the will of God, and not as an act of evil (murder). Without a central authority capable of fairly judging and enforcing these commandments, it would not be possible to judge or enforce them at all. Ex. without a properly instituted system of justice someone like Pinchas might likely have been killed by someone in retribution for his act of justice.
God stated the covenant would last until the end of the earth – which essentially means for as long as human beings exist. Thus it is an easy observation to make that the covenant for Noah's descendants was never explicitly repealed. Indeed, in and around Genesis 8:22 the covenant was promised by God to last until the end of the earth. This does not mean secondary or further covenants would not be made, such as the covenant at Mt. Sinai. However, the covenant of Noah is, and remains valid to this day. That was word of the Lord, as written in the bible.
if you believe in God but for some reason do not identify as a Muslim, Christian or Jew, your default position is to become a Noachide, not to become an Atheist. Many people who have become disillusioned with their faith and who reject their major prophet (ex. Jesus, Paul or Mohammed) throw the baby out with the bath water and fall into Atheism (or worse, a form of Idolatry in rebellion). But this is not what you should do. If you believe in God and want to follow his will then you should investigate the institution of bne'i Noach (Noachide-ism) before throwing your faith away.
Thus, being a Noachide is a very practical matter. This ties in with What We Do – what we do, is keeep God's commandments to Noah and his descendants in order to fulfill our duty as descendants of Noah and under God's covenant with Noah.