About the book of Habakkuk

Habakkuk lived in Judah about 600 years BC. Judah was the Israelite kingdom in the south. We know very little about Habakkuk himself.
The nation that ruled that part of the world until 612 BC was Assyria. In 612 BC, a nation called Babylon won a war against Assyria. Then the Babylonians ruled that part of the world. Both the Assyrians and the Babylonians worshipped false gods. Habakkuk thought that God should punish the people in Judah who were doing bad things.
God chose the Babylonians to punish the people of Judah. Habakkuk could not understand why God would use the Babylonians to punish his people. The Babylonians were very bad and cruel people. So Habakkuk complained to God. God explained to Habakkuk what he was doing. He would use the Babylonians to punish Judah, but in the end he would punish the Babylonians.
In chapter 3, Habakkuk prays to God. Now he understands better what God is doing. He says that he will praise God whatever happens. He knows that God is faithful.