Be recognized as one truly sent by the Lord only if his prediction comes true.

Jeremiah 28:1-17
The prophet who prophesies peace will be recognized as one truly sent by the Lord only if his prediction comes true.
In the fifth month of that same year, the fourth year, early in the reign of Zedikiah king of Judah, the prophet Hananiah son of Azzur, who was from Gibeon, he said the Lord will break the yoke of the king of Babylon within two years and took the yoke off the neck if the prophet Jeremiah and broke it
Shortly after the prophet Hananiah Had broken the yoke off the neck of the prophet Jeremiah, the word of the Lord came to Jeremiah: Go and tell Hananiah, you have broken a wooden yoke, but its place you will get a yoke of iron. I will put a iron yoke on the necks of all these nations to make them server Nebuchadnezzar.
Jeremiah said to Hananiah the prophet, he will be removed from the face of the earth. This very year you are going to die because you have preached rebellion against the Lord.  In the seventh month of that same year, Hananiah the prophet died.
Why?
The time proves the truth of Jeremiah's word. Any prophet who falsely claims to speak for God is under sentence of death.
Only the word sent by the Lord comes true. Time will approve who is the false prophet.
People like peace but if they do evil deed and do not return to the Lord, the destination is dead and disaster.
How?
Speak in true is the way of Lord, say yes to the true and say not to the false. Honest to be a man.