Why can't they see the Truth?

Read Isaiah 29.

This chapter could be labeled as bad news, good news.  First the "woe".  Ariel is a direct reference to Jerusalem, the city of David (v.1).  The city would come under siege by the Assyrians.  Indeed, Sennacherib surrounded Jerusalem in 701 B.C. but was unable to conquer it.  Notice in verse 3, that God takes personal credit for putting the city under such pressure.  And, He will protect the city this time.  Like a person with a bad dream, when awakened the frightening thing was not there.  The whole reason for God's judgment was to motivate them to repent.  But they did not.

Why could they not see what God was doing?  Why could they not hear the prophet's message and change their ways?

Their sin had caused them to become spiritually insensitive to the things of God.  They had blinded their eyes from seeing the truth and stopped their ears hearing what God was saying to them.  Their so-called spiritual leaders could not make sense of God's word.  Even reading the messages did not make sense to them.  They were religious (v.13) but their words of worship were empty because "their hearts are far from me."

Believing they had no accountability to the LORD, they took full credit for their lives.  Their thoughts toward the Creator included: "He did not make me" (v.16)

And now the good news.  What a change, "in that day," when the Messiah will return to rule the world from the city of Jerusalem.  "In that day" the Jews will hear the message and see the truth.  Justice will come to the oppressed and upon the "ruthless."  As a nation of God's people, they will acknowledge who Jesus is and give Him full credit for their lives.  

As the Apostle Paul looked forward to the day of Israel's national repentance, in Romans 9 he wrote of the same potter and clay comparison.  In Romans 11, he wrote of Israel's spiritual blindness and deafness.  His point was that this opened wide the door for the Gentiles to be "grafted" into God's plan of redemption.  As individuals, he wrote in Romans 10:12-13- "For there is no distinction between Jew and Greek; for the same Lord is Lord of all, bestowing his riches on all who call on him.  For 'everyone who calls on the name of the Lord will be saved.'"