How is Judaism to be maintained? It is a faith of a people, who see their line go back to Moses and Abraham, and whose experiences are recalled through symbolic practices.
There are two main experiences which define a Jew. There is exile with wandering, and suffering. Out of suffering comes the promise of hope; out of wandering comes the desire for returning to a homeland.
The first identity through history is that of Abraham the Patriarch (father figure) dated about 1800 BCE. Abraham received both the revelation of One God and the Promised Land for his descendants. He left Ur and polytheistic Persia for the Promised Land, Canaan (Israel).
There was a famine and the descendants went to Egypt for food and were enslaved. The story tells of ten plagues and then freedom under Moses, dated 1280 BCE, and receiving the Ten Commandments. They wandered through the wilderness for 40 years before returning to the Promised Land.
In 722 BCE the Assyrians took the Israelites from Canaan into exile. In 586 BCE the second Babylonian empire destroyed the Temple and took the Jews from Judaea just to the south. In 538 BCE the Jews returned but many stayed and prospered under the Persians. In 70 CE the Romans destroyed the rebuilt second Temple and by 135 CE all Jews had dispersed.
In Britain there were Sephardim and Ashkenazim Jews. Sephardim are Spanish and Ashkenazim refers to Germany. These two groups developed differently because the Jews had prospered in Islamic Spain until the Roman Catholic backed victory in 1492 which again sent those Jews wandering as both Muslims and Jews were thrown out. Others, called the Ashkenazim, were in Germany and spread east.
In 1290 Jews had been evicted from England, having been over taxed of their assets and at times massacred, and Jews were not allowed in again until the time of Oliver Cromwell in the 1640s who used them for trade and banking, having seen the prosperity they generated in the Netherlands. Those that came in subsequently were either Sephardim or Ashkenazim. They formed different synagogues but joined together in the United Synagogue of Great Britain.
Jews were seen as people of the Bible, if not all the Bible, and were well tolerated by the elite in this country. In Europe they were much more separate, distinct and seen as different. The view that the Jews had killed Christ, and then their leading roles in countries like Germany, led to their being scapegoated for social and economic problems, and oppression led to industrial scale murder in the Holocaust under the Nazi period.
Thus for the Orthodox maintaining practices is vital in order to recall their suffering and wandering, the faith of Abraham that remembers Moses, the Exodus, the destruction of the Temples and all subsequent suffering including the Holocaust.