I believe invoking God’s name in any way which diminishes His holiness or any of His Divine attributes is “taking the Lord’s name in vain.” In Psalm 8:1 we read, “O LORD, our Lord, how excellent is Your NAME in all the earth, who have set Your glory above the heavens.” The majesty of God’s name is manifested throughout His whole creation; “in all the earth” and “above the heavens.” All that He has created brings out His greatness, His power, and His wisdom. To invoke God’s EXCELLENT name in a flippant manner is to “take His name in vain.” Psalm 111:9 declares, “HOLY and AWESOME is His name.” The KJV reads, “HOLY and REVEREND is His name.” The word “name” speaks of one’s CHARACTER and here we learn (along with many other scriptures) that God is HOLY. And because He is “holy” He is to be “revered” (to be “held in deep respect and with reverential fear”). Again, any time His name is invoked without due respect and fear is to “take the Lord’s name in vain.”

We have a prime example of “taking the Lord’s name in vain” in Leviticus 19:11-12, “You shall not steal, nor deal FALSELY, nor LIE to one another. And you shall not swear by My name FALSELY, nor shall you profane the name of your God: I am the LORD.” This is NOT speaking of using the Lord’s name in profanity (as a “curse word”), but rather using the Lord’s name to convince others that you are telling them the truth, when in fact you are “LYING to them.” Some people say, “I swear on God’s name that I’m telling the truth.” To invoke His name in this way when you know your are lying is to “take the Lord’s name in vain.” Again, “Holy and reverend is His name” and to use His name while lying is to disrespect Him and His holiness. It is one of the worst forms of BLASPHEMY possible. Shame on the believer who would stoop to this behavior and dishonor the Lord who has saved you.  The truth is the believer should never have to “swear by His name.” The Lord taught this in Matthew 5:33-37, “Again you have heard that it was said to those of old, ‘You shall not SWEAR FALSELY, but shall perform your oaths to the Lord.’ But I say to you, DO NOT SWEAR AT ALL: neither by heaven, for it is God’s throne; nor by earth, for it is His footstool; nor by Jerusalem, for it is the city of the great King. Nor shall you swear by your head, because you cannot make one hair white or black. But let your ‘Yes’ be ‘Yes,’ and your ‘No,’ ‘No.’ For whatever is more than these is from the evil one.” The believer should be known for his integrity and honesty. He should not have to “swear at all” to prove that he is telling the truth or that he will make good on a promise he has made. The only exception to this would be if one is taking the witness stand in a court of law and is asked to put his hand on a Bible and swear that he will “tell the truth and nothing but the truth.” This is part of the legal system that we must abide by. But in everyday life the believer’s testimony to the world should be known and respected and thus he should never have to “swear by God’s name” or “swear on a Bible” (which is basically the same thing as “swearing by God’s name”).

In closing I will add that we can “take the Lord’s name in vain” in many other ways. For example, if we are speaking “the name of Jesus Christ” in conversation in a light and flippant manner we “taking His name in vain.” Or perhaps we are witnessing to the lost and speaking Christ’s name, while at the same time arguing with a raised voice. If we do, we are guilty of “taking His name in vain.” To do so is to bring dishonor to His name. It is tantamount to what you said, “calling oneself a Christian but living like the world.” As we think of this subject, may we “guard our tongue” when thinking of invoking His name. Better yet, may we ask the Lord to guard our tongue as David did in Psalm 141:3, “Set a guard, O LORD, over my mouth; keep watch over the door of my lips.”  (DO)  (576.1)