The last chapter of Malachi summarizes the whole of the prophetic message found in this little book.
The chief exercise of worship for the Jews was sacrifice, which was only performed in the temple through the priest. The temple was the place where sinful men could approach God. But for us, Christ is the temple, the sacrifice, and the priest.
Amos' oracles, addressed to the pagan nations and to Israel, conform directly to the Mosaic covenant. God's universal justice is the predominant theme of this minor prophet.
As Christians, we are in covenant with God, and He has called us into family court, not to have us imprisoned, but to restore us in fellowship.
Jonah's different responses to his and Nineveh's deliverances clue us in to what the great message of this book is, because he is not just the prophet delivering God's message, he is also the one to whom God is delivering His message to.
Meet with Habakkuk, worship with Habakkuk, and emulate Habakkuk.