Can Acts 2 be used to show that people are no longer under the Law and are saved by believing in the crucified and resurrected Christ?

Les teaches that God was still using Israel on covenant ground and had not abrogated those promises. He had not yet told anyone to stop temple worship or to stop keeping the Law. In Acts 2, Peter is still on covenant ground, addressing the house of Israel—Jew only—and accusing them of crucifying their Messiah. Les points out that the revelation that one is no longer under Law and is saved by believing in the crucified, resurrected Christ cannot be found in Acts 2 yet. He contrasts this with the later language in Galatians, Romans, and Corinthians, where salvation is put on Christ's death, burial, and resurrection. So Acts 2 should not be forced to teach that doctrine.