Were Peter and the early Jewish believers in Acts still keeping the law after Jesus rose?
Yes, Peter and the early Jewish believers in Acts were still keeping the law after Jesus rose. They remained law-keeping Jews, and Peter viewed entering a Gentile house as unlawful. Even after Christ's crucifixion, resurrection, and ascension, the prophetic program continued, with Peter expecting Christ to still set up the kingdom if Israel believed.
Les explains that even at this late date, the Jewish believers such as Peter, the eleven, and those who had believed during Christ's earthly ministry and early in Acts were all Jews as far as can be told, and they were law keepers still keeping the law. He notes Peter was a law-keeping Jew coming into a strange area, into Cornelius's house filled with Gentiles. Peter was uncomfortable even though God had made sure this was what He was going to do. Peter said it was an unlawful thing for a Jew to keep company with or come to one of another nation, and Les stresses the only reason Peter went was that God forced the issue. Everything was still in the prophetic program: Christ had been crucified, buried, risen, and ascended, but by Acts chapter three Peter claims Christ will still come and set up His kingdom if Israel will only believe Him. But they don't, and then comes a place of change.