Malachi 1

Chapter 1:1-5
This chapter starts out about God's love for his people. And leads quickly into His people questioning everything He does, much as we do today. It talks of Jacob and Esau, brothers who fight over their inheritance. Esau is to serve Jacob, God decided that before either boy was born. But Esau's dishonesty and vengeance leads God to favor and protect Jacob. He proclaims Esau's people will be known as 'the people with whom God is forever angry'; makes me appreciate that I am not an Edomite. The point of these 5 verses is that God has the ultimate power and God is in control of our world and our lives. He is the potter and we are the clay. It is His choice and His right to do with us as He desires. He is the creator and we are the creatures.
Chapter 1:6-14
These next 8 verses are about the defiling of the sacrifices offered to God and therefore the defiling of God himself, by the Israelites. By offering sick, mutilated, stolen, or otherwise imperfect sacrifices upon an alter to God they were saying that He didn't deserve the best and therefore was only worthy of what they thought was good enough. Their and our lives should be living sacrifices to God. If we only offer what's 'good enough' or leftover we repeat the same sin as the Israelites, which didn't want to bring anything valuable to God. What we give God reflects our true attitude towards Him.