Why shouldn't we be too hard on the Israelites for their resistance to Gentile inclusion?

Les explains that Israel was God's covenant people, called to remain a separated people. They were never to intermarry with anyone outside Israel and were to have no real social contact with the pagan peoples around them, though they had to do business with them. God never instructed the Jew to proselyte or evangelize Gentiles. Although God wanted the Gentiles, He did not want it by Jewish proselyting or evangelizing, because He was dealing strictly with the covenant nation He would set aside and make different. This background explains why Jews were upset when Paul later went to the Gentiles. Les says we shouldn't come too hard on the Israelites because for almost two thousand years God had been telling and proving they were different and separated, and it took a long time to get that out of their system. That is why Paul and Peter had the Galatians 2 confrontation: Peter could sit and eat with Gentile believers at Antioch, but when fellow Jews came from Jerusalem he withdrew.