The name of God
“Thou shalt not take the name of the LORD thy God in vain” (Exodus 20:7a).
The Third Commandment unveils the worship life of a person by examining how he uses God's name. If God is being honoured and worshipped in a man's heart, the name of God will also be held in reverence. Praise, adoration, and honour being ascribed to God's name is an essential element of worship. Both our hymnbooks and the Bible feature doxologies.
A name stands for a person, represents him, and in a sense is him (he). Our justice system recognizes this by laws concerned with libel, defamation, and slander. Those who have a good name treasure it, perhaps above all things.
The very first item in the Lord's Prayer to the Heavenly Father is, “Hallowed be thy name”. God takes very seriously crimes against Himself by way of abusing His name. Through this Third Commandment, He also helps us see the alienation from God that lies at the root of this everyday, socially acceptable, yet sinful behaviour.
God's name is taken in vain by cursing. This is calling upon God to damn someone out of personal hatred for them. It is the ultimate murder, in effect wishing an enemy would go to hell. Although it will be necessary for God to send people to hell who reject His Son, it is not what His loving heart desires for them. The Bible tells us that God “is longsuffering to us-ward, not willing that any should perish, but that all should come to repentance” (II Peter 3:9b). He does not want His name attached to the malice of hateful cursing. “But God commendeth his love toward us, in that, while we were yet sinners, Christ died for us” (Romans 5:8).
God's name is taken in vain by swearing. This is about the light use of God's name in everyday yes-and-no conversation. Swearing has a certain usage in courtrooms and is essentially calling God to witness the truth of a statement (and inviting His judgment upon lying). God does not want His great name profaned with the casual use of “by God” or any such oaths. “But let your communication be, Yea, yea; Nay, nay: for whatsoever is more than these cometh of evil” (Matthew 5:37).
The classic case of using God's name in vain is simply to use it as a common interjection like the thoughtless “OMG” or by casually reciting the name of Jesus Christ. I can't imagine how many charges will be outstanding against those that incorporate such things into their ads and product names.
The rest of the verse quoted at the beginning is, “for the LORD will not hold him guiltless that taketh his name in vain” (Exodus 20:7b). This Commandment of all the Ten is most frequently excused in the minds of people. God does not. What matters most is what God thinks and how He judges.