Matthew 20

Matthew 20 tells the story of a landowner hiring workers for his vineyard.  He hires them in five different groups, and none but the first group had an agreed upon wage.  Each of the different groups end up being paid the same amount, despite the fact that they all worked different amounts of time.

This appears to be a picture of the Jews and Gentiles, as the Jews had the initial covenant (the Abrahamic), which is then inherited by the late-coming Gentiles.  Also, the vineyard is a common picture of the people of God (faithful or not).