Why did Paul's no-difference message rile the Jews?
The message angered them because God had set Israel apart from the pagans, commanding separation and no intermarriage. For the Jews of Paul's day, that longstanding tradition of being distinct made the claim that Jew and Gentile now stood alike before God deeply offensive. Thus, Paul's insistence on no difference contradicted their cherished identity.
Les teaches that Paul got in trouble with his Jewish people because he maintained there was now no difference between a Jew and a Gentile. Back in Exodus, as soon as God pulled Israel out of Egypt, He told them, "You're different. I'm going to make you different. I'm going to set you apart." He instructed them not to have anything to do with the pagans around them and not to intermarry with them. Les explains that this is why it was so hard for the Jews of Paul's day to suddenly come out of that tradition that they were different, and then to have this little Jew say, "There's no difference." That is why it riled them. Paul also says all have sinned, not just the Gentiles, and come short of the glory of God.
Even the righteousness of God which is by faith of Jesus Christ unto all and upon all them that believe: for there is no difference: