Gentile converts we’re interested in following Jesus not Jewish customs. Jews had bled and died for these customs during their long and difficult history. It was no small thing to simply abandon them. In the early days of Christianity, the newly forming church seemed to be working out a mediating position giving Gentiles Christians more freedom but yet respecting Jewish customs.
However, the success was short lived. A complete and irrevocable split would happen well before the turn of the first century. The Jewish revolt from Rome had begun in earnest in the mid 60’s. The Roman emperor had had enough. Titus and his legions marched upon Jerusalem. Complete and total destruction was the military plan for dealing with these pesky Jews who had been for too long a pain in the eastern side of the Roman Empire.
As Jewish patriots prepared for the onslaught, the Jewish Christians of the city decided it was foolish to fight Rome. Their hope was in a heavenly city not made by human hands, so they fled. This was viewed as an ultimate act of treason by “real” Jews. Jerusalem was destroyed in A.D. 70 and in the following months all the synagogues in Palestine were also obliterated. For the survivors of this slaughter one point was clear: to abandon Jerusalem in its hour of need was to abandon Jewishness. As synagogues we’re rebuilt a law was quickly passed prohibiting any Jewish person who claimed to be a Christian from entrance into the synagogue and thus Jewish life. The split was complete. Jewish Christians now had to decide if they were Jewish or Christian they couldn’t be both.
(For all of these snippets of history I am indebted to Bruce Shelley)