"Ye offer polluted bread upon mine altar; and ye say, Wherein have we polluted thee? In that ye say, The table of the LORD is contemptible." Malachi 1:7
Read Malachi 1; Nehemiah 13.
The priests in Israel lost their passion. They grudgingly offered sacrifices, knowingly placing imperfect animals upon the altar.
The offering of sacrifices was a form of worship. We don't offer animal sacrifices anymore, but we do worship on many different levels. In your daily life (which we are to offer as a sacrifice) are you doing your best for the Lord? 
- When you pray, do you fall asleep or let your mind wander?
- When you read the Bible, do you scan the words instead of allowing the Holy Spirit to speak to you?
- When you sing do you make a joyful noise, presenting to God your very best?
- When you serve in your church, do you give 100% effort?
- When you are at work, are you honoring God (acknowledging that He is the one that provided the job) and giving your 100%?
- When you fellowship with friends and family, do you remember that God tells us to 'minister' to one another, and therefore reflect this in your communication?
I must not offer my sacrifices grudgingly, as the priests did, with only a half-hearted attempt to please God. Rather, I must pour my all on the altar with the very best that I can give—with a passion bent on meeting the passion God has for me.
In what ways are you offering sacrifices of worship to God?
"I beseech you therefore, brethren, by the mercies of God, that ye present your bodies a living sacrifice, holy, acceptable unto God, which is your reasonable service.
And be not conformed to this world: but be ye transformed by the renewing of your mind, that ye may prove what is that good, and acceptable, and perfect, will of God." Romans 12:1
