And the Lord sent an angel, which cut off all the mighty men of valour, and the leaders and captains in the camp of the king of Assyria. So he returned with shame of face to his own land. And when he was come into the house of his god, they that came forth of his own bowels slew him there with the sword. 2 Chronicles 32:21
The King of Assyria sent a messenger to King Hezekiah. The messanger told them that none of the other gods of the other nations had been able to protect them. The messenger said that their God would not be able to protect them. He said that the Assyrians would destroy Jerusalem and everyone in their path. However, God in heaven heard them and sent an angel to kill thousands of the Assyrians. God showed them that he was alive and powerful! It is not a wise thing to boast against God because He cares about his name!