Most importantly, the people whom we call Jews today are, for the most part, not the same ethnic group to which Paul refers in the second chapter of Romans. Revelation 2 9 and 3 9 bear this fact out.
Jesus' disciples were not Jews, except for Judas Iscariot: they were Galaleans.
When it comes to Paul being a "Jew", we have to make a distinction between Saul, who had made it his mission to kill all Christians and who had progressed further in the religion of the Pharesies than any of his countrymen (Gal.1 13.)
Jesus was not born into a family of modern-day Jewish stock: He was born into the Hebrew tribe of Judah, which is not really the same ethnicity.
The reason the Jews were kicked out of so many European countries was because of their unfair moneylending practices and attempts to monopolize control of commerce.
Piper will mention some obscure Ukrainian guy but will not mention the fact Lenen and Trotsky were Jewish and the number of Christians killed under Russian communism.