become like me: Paul was a devoted Jew. He stopped trying to earn righteousness and accepted God's free grace in Jesus Christ. Now, Paul asks these Gentiles to follow his example instead of adopting the Jewish practices he left behind. Paul's advice throughout the rest of the letter (4:12–6:10) comes from this single command.
You have done me no wrong: Similarly, the Galatians should not mistreat Paul now but should continue to warmly accept his ministry and message.