“Boast not against the branches.” (Rom. 11:1) How would one do this who believes Jesus of Nazareth is the Messiah ? Any believer who refers to the Jews in a derogatory manor would violate this command from God. Of course, it would be a similar sin of arrogance to say ‘Those Italians / Mexicans / Arabs / French, etc. . .’ in a defaming manor. However with Israel it is different. The basis of their existence contains the root for the world’s salvation. “But if thou boast, thou bearest not the root, but the root thee.” If we have life, it is because of what God accomplished through the Israel. “And in that day there shall be a root of Jesse, which shall stand for an ensign of the people; to it shall the Gentiles seek: and his rest shall be glorious.” (Isaiah 11:10)