Buddhists, Christians and Muslims each grew from a few thousand people into the many tens of millions who live in the world today, while Jews and Zoroastrians did not. The number of Jews, even before the Holocaust, was only three times the number of Jews in the first century, and the number of Zoroastrians (called Parsees in India) in the 20th century was much smaller than it was in the first century.
Jews usually explain their steadily decreasing percentage of the world’s total population in terms of a long history of persecution, forced apostasy and physical slaughter. But there is another important factor that is almost always overlooked. While Buddhism, Christianity and Islam are missionary religions; Judaism and Zoroastrianism are definitely not.
The spread of Buddhism from India to China; the spread of Christianity throughout Europe; and the spread of Islam from Morocco to Indonesia were all the result of missionary activities. These activities still continue. Half of all Koreans have become Christians in the last half century because of Protestant missionaries. In less than 200 years, Mormon missionary activities produced a Mormon population equal in size to a Jewish population that was born more than 3.000 years earlier.
Jews and Zoroastrians, who have never engaged in major missionary activities, have remained largely confined to the descendants of the nation in which they originated. For example, Jewish and Parsee communities in India and China were descendants of immigrants; and not descendants of converts, as are almost all Christians and Muslims in India and China today.
This does not mean that Jews and Zoroastrians were, or still are a pure race. Anyone who visits Israel knows that Jews from Ethiopia look mostly like Ethiopians, and Jews from Poland look mostly like Poles. There has always been intermarriage with some conversion to Judaism; and over the centuries Jews begin to resemble the local inhabitants. Also, even though the majority religion usually prohibits its members from converting to Judaism, it did not always succeed.
Christians and Muslims have often criticized Jews for being a clannish and inbred people because Jews do not include a great variety of different racial, ethnic and national groups. This is slowly changing in the U.S. where thousands of non-Jews, many of them Asians, convert to Judaism every year.
I do not know why Zoroastrianism did not develop a missionary impulse, but the main motive for missionary work is lacking in Judaism. Jews do not believe that we alone have the wisdom that will provide all humans with true enlightenment; nor do we believe we have the only faith that will guarantee all humans admission into heaven.
Judaism teaches that the righteous of all nations have a place in the world to come. Jews must not bow down to statues or believe in more than one God, but that does not apply to other nations and peoples. As long as non-Jews practice justice and mercy they will receive God’s blessings.
As the Biblical prophet Micah declares, “God has shown you, O human, what is good and what the Lord requires of you: act justly, love mercy, and walk humbly with your God.” (Micah 6:8) This is true now and will be true even in the Messianic Age, when “They will beat their swords into plowshares and their spears into pruning hooks. Nation will not take up sword against nation, nor will they train for war anymore. Everyone will sit under their own vine and under their own fig tree, and no one will make them afraid, for the Lord God has spoken. All the nations will walk each in the name of its gods, and we will walk in the name of the Lord our God for ever and ever. (Micah 4:3-5)
So while Jews have no missionaries, Judaism does most certainly welcome everyone who desires to become Jewish to join us. Many Jews even encourage some people who no longer believe in their childhood religion, to study Judaism and if they so desire, to become part of the Jewish People. That is why it is so sad that the number of people who convert to Judaism in the State of Israel has been in decline in recent years.
According to Orthodox Rabbi David Stav in The Jewish Daily Forward the state-run, ultra-Orthodox controlled, Conversion Authority, working slowly and bureaucratically, has deterring thousands of immigrants from the former USSR, who have Jewish lineage but who are not halachically Jewish from becoming Jewish. The anti-coversion ultraOrthodox mind set still makes conversion as difficult as possible to this day.
Jews are not missionaries, and people who are committed to their own religion should be respected. As long as they “act justly and love mercy” they will receive God’s blessings. But making it hard for non-Jews to become Jewish is a terrible mistake, Rashi, the greatest of our Bible commentators, taught that Jews started seeking converts from the very beginning, when he interpreted a verse that states that Abraham made souls in Haran, to mean that Abraham and Sarah made converts.
And the Talmud (Sanhedrin 99b) condemns those who push potential converts away by relating that Isaac and Jacob pushed away Timna, the sister of Lotan, who wanted to become Jewish. So she married a son of Esau and one of her descendants was Amalek, who attacked Israel shortly after they escaped from Egypt. If, instead of being pushed away, Timna had become Jewish, Amalek would have been on our side, and not on the side of our enemies.
This applies to the tens of thousands of ex Soviet Jews in Israel who have been pushed away from converting to Judaism. Indeed, Rabbi Yohanan says the Jews were oppressed and enslaved in Egypt because Abraham didn’t try to influence some captives that he rescued, to become Jewish. (Talmud Neddarim 32a)