“The person who cheats will be cursed. He has a male animal in his flock and promises to offer it, but then he offers to the Lord an animal that has something wrong with it. I am a great king,” says the Lord All-Powerful, “and I am feared by all the nations.”
Malachi 1:14 (NCV)
God’s gifts are priceless, offer Him worship that is reverent and genuine, otherwise you only deceive yourself.