Sac·ri·lege (n.): blasphemous behavior; the violation or profanation of anything sacred or held sacred. The Third Commandment teaches that we should not take the name of the Lord in vain (Exodus 20:7). That does not just mean that we are prohibited from referring to God irreverently in our speech. If you are a Christian, you are a representative of Christ. You carry the name of Christ inasmuch as you are a Christian. With every action, you are communicating something about Christ. If those actions are sinful, then you are representing Christ unfaithfully—communicating a lie about the One whose name you bear. You are taking the name of the Lord in vain by your actions, and at the same time, bearing false witness of who He is (Exodus 20:16). And this does not just apply to children of God dishonoring the family name. Christian or not, we are ALL image-bearers of God (Genesis 1:27). We are representations of God—good or bad. No wonder sin is so painful to Him. Every sin is a lie about the character of God. It's offensive. ...

Exodus 20:7 and Exodus 20:16