What does Acts 17:3 mean?
The Jewish interpretation of the Messianic prophesies in the Old Testament are very specific. The Messiah is a warrior or a king who will rescue Israel from foreign occupation, bring peace and prosperity, and renew the nation such that other nations will give them honor. This is a literal reading of the prophecies, but it is incomplete. Messiah as worldly Savior is for the millennial kingdom. The Messiah—Jesus—first came to save the world from the eternal death brought on by sin. To do this, the Messiah had to die and rise again.This is what Paul preached in Pisidian Antioch (Acts 13:26–47) and likely every other city with a strong Jewish population. He can give context to several prophecies that don't seem to agree with the Warrior-King theme. Isaiah 50:6 speaks of one whose enemies beat Him, pull out His beard, and spit on Him. Isaiah 52:13—53:12, which many Jewish people struggle to ignore, describes the Messiah as someone who is despised, pierced for our transgressions, and heals us through His wounds. This idea that the Messiah must suffer and die is difficult for those who think more of the Son of Man in Daniel 7:13–14 who is given dominion over the nations.
"Christ" is from the Greek root word christos; it is Greek for "anointed one" as "Messiah" is the Hebrew form. "Explaining" is from the Greek root word dianoigo. Literally, it means to open what has been closed. Metaphorically, it means to enlighten, to open one's mind. It is used in the story of the two disciples whom Jesus met after the resurrection; the men's eyes were opened (Luke 24:31) after Jesus opened the Scriptures to them (Luke 24:32). "Proving" is from the Greek root word paratithemi. Literally, it means to set something nearby; metaphorically, it means to explain or to set the meaning of something before someone else. The word is also used in Acts 14:23 of the elders that Paul's group committed to the Lord.