Exodus 20:7
You shall not take the name of the Lord your God in vain, for the Lord will not leave him unpunished who takes His name in vain.
“Our help is in the name of the Lord who made heaven and earth” (Psalm 124:8). His name is a strong tower and mighty fortress (Proverbs 18:10). It is by His name that covenants are made. There is not another name in existence that carries as much respect, worth, and power as that of the Lord’s.
As a Christian, you “bear” God’s name. Just as a bride takes on the name of her husband, you have taken on the name of your God. From this point on, you are associated with the same name that is above every other name (Philippians 2:9). Your words, your actions, and your entire life must accurately represent the King of Kings. To take the Lord’s name and to vainly use it for your own glory is as simple as misrepresenting Christ to your friends. Using the Lord’s name as an expletive is probably the least of your worries when it comes to breaking His third commandment.
Do not let the fact that this commandment was learned in elementary school allow you to overlook its importance. Your God rightfully disciplines those that run His name through the mud. While some may do it through expletives, most of us do it through ungodly lifestyles.