Why were the believers still going only to Jews seven years after Pentecost?

Les explains that the scattered believers traveled as far as Phenis, to Cyprus, and up to Antioch in Syria, preaching the Word to Jews only. Since no New Testament had been written yet, the Word they had was the Old Testament. This was long after Pentecost, about seven years, and they were still adhering to Jesus' commandment in Matthew: go not in the way of a Gentile, but go only to the lost sheep of the house of Israel. Les says this helps explain why the Lord had to make such an emphasis to Ananias about the purpose of saving this Jewish zealot, showing that a change of direction was coming. From Genesis 12 until Acts chapter 9, God was dealing with the nation of Israel, not exclusively, but almost.