Jeremiah 19-20: Jeremiah's Predicament

Poor Jeremiah.  He hears the word of the Lord and feels compelled to deliver God's message to the people.  So when God says go to the Valley of Hinnom, which lies outside the city of Jerusalem, and buy a clay pot he does so.  There he proclaims the word of the Lord, and demonstrates God's promise by breaking the jar.

 Listen! I am going to bring a disaster on this place that will make the ears of everyone who hears of it tingle. For they have forsaken me and made this a place of foreign gods; they have burned sacrifices in it to gods that neither they nor their fathers nor the kings of Judah ever knew, and they have filled this place with the blood of the innocent. They have built the high places of Baal to burn their sons in the fire as offerings to Baal—something I did not command or mention, nor did it enter my mind. So beware, the days are coming, declares the LORD, when people will no longer call this place Topheth or the Valley of Ben Hinnom, but the Valley of Slaughter. - Jer. 19:3-6 NIV

You would think that would make the people tear their clothes and repent, but instead they beat Jeremiah and left him in the stocks overnight.  So Jeremiah runs to the Lord.

O LORD, you deceived me, and I was deceived;
you overpowered me and prevailed.
I am ridiculed all day long;
everyone mocks me
Whenever I speak, I cry out
proclaiming violence and destruction.
So the word of the LORD has brought me
insult and reproach all day long. - Jer 20:7-8 NIV

Unlike the people of Israel, who cannot be faithful, Jeremiah has no choice but to be true to God. 
But if I say, "I will not mention him
or speak any more in his name,"
his word is in my heart like a fire,
a fire shut up in my bones.
I am weary of holding it in:
indeed, I cannot. Jer. 20:9 NIV

Jeremiah knew that the only way to endure the fiery wrath of God was to have his fire burning in his heart.