God finally has had enough.  I don't know the timeline between the visions, but there was more than enough time for Amos to warn the people and for the people to repent.  But they didn't.  So God spoke to Amos again in a vision.

Amos 7:7-9  "Thus he showed me: and, behold, the Lord stood upon a wall made by a plumb line, with a plumb line in his hand.  And the Lord said to me, Amos, what do you see?  And I said,  A plumb line.  Then said the Lord,   Behold, I will set a plumb line in the midst of my people Israel:  I will not again pass by them any more:"

Have you ever used a plumb line?  I used to wallpaper, and if you didn't get the first strip straight, the entire job would be crooked.  So I used a plumb line and the law of gravity gave me a perfect vertical line to begin on.  It is either straight or it isn't.  And Amos got the message.  Israel wasn't straight.

So God gave the last vision to Amos.  He did not tell Amos to warn the people.  The vision was for Amos.  God wanted Amos to see what God saw.  That the people were out of line.  Crooked.   And God had forgiven the people in the first vision and ceased his plan in the second vision.  All for Amos.  Because Amos asked God.

Don't you wonder how long God will tolerate his American people.  We began a nation based on the moral law of the Bible.  We had high ideals.  But little by little we have compromised our values.  Our nation is no longer a Christian nation.  The latest statistics say that the majority of Americans answered "None" when asked the question, "What is your religion?".

It will be horrible to hear God say, "I will not again pass by them any more."