|Keep reading to see why this photo is relevant|
I remember doing a corporate confession meditation several years ago which focused on this broader aspect of keeping the third commandment and what it means to take the Lord's name in vain. Some illustrations might be helpful when thinking through the fuller sense of what it means to take God's name in vain - it is more than just using God's name as a cuss or frivolously speaking of God, though it certainly includes those things. I encourage you to read the article linked above, then read my illustrations below.
In marriage, traditionally a bride takes her groom's name. She is then known by the last name of her husband. That bride may be a faithful wife, keeping her marriage vows in both letter and spirit, never wavering in her faithfulness. In this way she would be rightly taking her husband's name. But, the wife may also take her husband's name in vain. She has really taken his name upon her in the marriage vows of the wedding ceremony, covenanting to be his "lawful wedded wife", but if she then lives a life of infidelity to her husband (even despite his faithfulness to her) she has taken his name in vain. This does not mean that her wedding vows meant nothing - they were and still are a binding covenant - but it means that she has vowed them in vain, for she is not living up to the vows she made or the new name she received by covenant. It is like this for God's people.
The church corporately is the bride of Christ (Rev. 21:9), promised to one husband (2 Cor. 11:2), the Lamb (Rev. 19:7; 21:2), and we are wed to Christ by covenant. As such, we have taken his name. We are Christians, "Christ-ones", after all. So if we have been baptized into the Triune name of God, if we have put on Christ in baptism and are united to him by covenant, yet live in such a way that the watching world sees no discernible difference between the church and the unbelieving world around us, we have taken Christ's name in vain. Therefore, as people bearing the triune name of God upon us, we ought to live in a manner worthy of the one to whom we are wed.
As well as being described as the bride or wife of Christ, God's people are also described as his children (Rom. 8:16; John 1:12; 1 John 3:1). God is our Father, and when God places the family name, the name of God the Father, Son and Holy Spirit, upon us in baptism, we are pronounced to be sons and daughters of our Heavenly Father. As such, we are now charged with the high calling of being imitators of our Father (Eph. 5:1), to bear the family resemblance and to obey the will of our Father. This obedience to God our Father is a major aspect of our gospel witness in the world (Phil. 2:15; 1 John 3:10; 5:2).
Now, we've all seen children who were a disgrace to their parents...perhaps we can recall a time when we ourselves were a disgrace to our parents...at least in an isolated episode. We can look at the life of David, who, along with some good sons, had some real stinkers. We look at David who, although not perfect himself, is described by God as being a man after God's own heart. Then we look at some of his immoral and ungodly sons. They were the type of men that bore their family name in vain. They should have acted like sons of David, the God-praising, fearless warrior, wise ruler, etc. Instead, these sons of David were disgraces to him, some even seeking to kill him. They bore their family name in vain; they were not a blessing to their father but a curse to their parents (Prov. 10:1). Like a child reflects either negatively or positively on his or her parents, so the church may either bear our family name as a positive witness or a disgraceful and inaccurate reflection of our Father.
I was on a backpacking trip to the big island of Hawaii once with a friend. I had a Canadian flag sown onto my backpack and in my past travel experience, this has always given me a fairly warm reception in foreign countries (south America and Europe feel much more foreign than Hawaii did, mind you). Well, one day my friend and I were sitting on a beach in Kona, resting after a lengthy multi-day hike to view some active volcanoes. We heard a loud disturbance coming from across the water and looking up we noticed a Zodiac full of naval servicemen being taken back to their frigate anchored off shore. We listened as the very obviously plastered soldiers cursed, swore, shouted and puked their was across the water to the waiting ship. Looking out at the ship we noted that it proudly flew the flag of our own home and native land from the stern of the vessel. I have to say that, along with the entire beach of tourists and locals watching this production, we judged these service men to be a pretty poor reflection upon the nation they represented. In fact, for nearly the first time in my life (at least since the last time Canada lost to another nation in an international hockey tournament) I was embarrassed to be wearing the Canadian flag. They were being very poor ambassadors of their nation in this foreign port. My friend and I got some dirty looks from people who likely suspected we too belonged on that ship.
As Christians, we are citizens of heaven (Phil. 3:20). More than citizens only, we are also soldiers serving in the cause of the gospel (Phil. 2:25; 2 Tim. 2:3). Even more than that, we are ambassadors for Christ in the cause of the gospel (2 Cor. 5:20). God makes his appeal to lost people through the message we bring, the message of Jesus Christ crucified, risen and reigning. But if those who are supposed to be ambassadors for Christ, his representatives in and to a lost world, are themselves poor pictures of what citizens of God's kingdom ought to live like, then we are bearing Christ's name in vain, taking God's name in vain. We are like the disgraceful soldiers who gave a bad name to their country. If people can't look at us and see a faithful (albeit imperfect) reflection of Jesus Christ, we bear his name in vain.
As the Bride of Christ, as children of our Heavenly Father, as Ambassadors of the Triune God ministering in the power of the Spirit, do not take the name of the LORD your God in vain.