Why is Isaiah 53 an appropriate passage to use when approaching Jewish people about Christ?

Isaiah 53 remains an appropriate portion of Scripture for approaching Jewish people because it presents the finished work of Christ and His First Advent. The context shows the Ethiopian official reading Isaiah the prophet, specifically Isaiah 53, and calls it still appropriate for approaching Jews about Christ.

Les teaches that Isaiah 53 is still an appropriate portion of Scripture for approaching Jews about the finished work of Christ and His First Advent. In the narrative, the Ethiopian official had been to Jerusalem to worship and was returning in his chariot, reading Isaiah the prophet. He was reading from Isaiah 53. The Holy Spirit then directed Philip to join himself to that chariot, showing God's sovereign interest in the situation.

Acts 8:28

Was returning, and sitting in his chariot read Esaias the prophet.

What does Les say is the value of Isaiah 53 when witnessing to Jewish people?

Isaiah 53 remains an appropriate portion of Scripture for approaching Jewish people, as it presents the finished work of Christ and His First Advent. It is still useful in Jewish evangelism, pointing to Christ's atoning work and His coming. This makes it valuable when witnessing to Jewish people.