Sons of Abraham

Jesus said to them, “Have you never read in the Scriptures:
“‘The stone the builders rejected
    has become the cornerstone;
the Lord has done this,
    and it is marvelous in our eyes’

“Therefore I tell you that the kingdom of God will be taken away from you and given to a people who will produce its fruit. Anyone who falls on this stone will be broken to pieces; anyone on whom it falls will be crushed.”

- Matthew 21:42-44

There are two ways to encounter the Son of God, and both of those ways end in death.  It is better by far to be broken than to be crushed, because if you're broken, that means you can be put back together.  To be crushed is to be decimated beyond recognition.

Jesus is the cornerstone that was taken outside the city and rejected.  But the chisel was taken to that Rock and fashioned into a cornerstone.  This hearkens to Hebrews 5:8 - "Although he was a Son, he learned obedience by the things which he suffered."

But again we circle back round to fruit, and the Kingdom of God has been given to those who will produce the Kingdom's fruit.  These are the sons of Abraham that John spoke of in Matthew 3 - "I tell you that out of these stones God can raise up children for Abraham."

So then, Jesus who was rejected has been fashioned into the Stone who then fashions those who have been broken - both the good and the bad - into those who bear the wedding clothes of righteousness; this is the same righteousness that was reckoned to Abraham.  And so they become the living stones, the sons of Abraham - all through Jesus, the Son of God.

Like Father, Like Son.

Which of the two did the will of his father?”
“The first,” they answered.

- Matthew 21:31

With this parable, Jesus instructs them of their error by pointing out that those who don't follow the Father at first but then later repent are doing the right thing over those who say they will follow but do not.

But there's a sweeter, deeper dynamic than the issue of the parable at hand.  This is probably the only extended dialog with the religious elite noted in the Bible.  Jesus is taking the time to reason with them through parables.  They won't answer His question in the previous section: was John's baptism ordained by God or just another human idea?  To put a fine point on it, they won't take a stand.  They are taking as politically correct a position as they could.

They start out by asking Him a direct, confrontational question.  But Jesus refuses to "knock that chip off their shoulders" until He gets them to take a stand of their own.  Because it seems they are honestly more comfortable in their scrutiny and judgment of Him than they are in choosing whether He's the "real deal" or not.  So He addresses them indirectly with a parable and then, after they answer His question about that parable, He gets back around to John endorsing him as one who needed to be heeded.

(Regarding their original question about the source of His authority, the documentation of this answer to them in that area is found elsewhere in the gospels. See Matthew 5:36, 37 and Matthew 10:25 are just a couple incidences.)

But the deeper dynamic is this: Jesus meets with us even in the thick of our contention with Him.  Don't be surprised when He confronts us in our struggles with Him.  But neither be surprised that He will likely not answer us in the manner that we expect.  He doesn't play by our rules.