The second commandment is “You shall not take the name of the Lord your God in vain.” This formulation is found in Exodus 20:7 in the midst of God speaking the Ten Commandments to Moses. Clearly, this commandment establishes that we are to always give proper respect to the Holy Name of God: to the Father, to the Son, Jesus Christ, and to the Holy Spirit – never using or speaking His name in an unholy or insulting/blasphemous way. Likewise, we are to speak respectfully of holy things – and never with irreverence. Finally, this commandment addresses oaths and the wrong of falsely swearing an oath.
Upholding the reverence due for God’s name includes both our care to use God’s name only to glorify, praise, or petition God, and through our fitting witness to God by living our faith and sharing it with others. To speak God’s name as an “interjection” (that is, as an abrupt or thoughtless expression of sentiment/emotion) is accordingly an abuse of His name and contrary to such reverence; such problematic use of interjections includes the sadly popular use of the text message acronym “OMG” as an expression of surprise – even when joyfully surprised. Blasphemy, which is to insult God or to speak in defiance or hatred of God, is directly contrary to this commandment – and is therefore a grave sin. Finally, to take a false oath in the name of God is an act of “perjury,” whether in formal settings such as dishonestly taking an officially sworn oath, or in a more informal way of saying we swear by God’s name while telling a lie – as though we are asking God (who is the Truth) to vouch for our lie.
The use of curse words – which is properly understood as calling down words of harm on another (whether God or another human being) – also are an offense against this commandment. Likewise, it is commonly understood that the use of vulgar or “profane” language is included in sins against this commandment. While such curse words and vulgarity may not always directly relate to reverence for God’s name, the common consequence of scandalous or injurious speech allows us to see these types of acts within this second commandment – as such speech causes harm to others who may be innocent.
As food for thought beyond our list of sins against the second commandment, consider that “to take His name in vain” is to say it without the right intention of wanting God near to us. Whenever we call upon the name of the Lord, we ought to intend to open ourselves to His presence, allowing Him to be all the more present to us in that moment of calling out to Him. As such, it is a vain (and sinful) act to call out the Lord’s name when we want nothing to do with Him – which is exactly what happens when we use His name in an unholy way, as a curse, or as an insult: we are committing a contradiction as in the spoken word of His name we are at once asking Him to be near while at the same time in our mind and heart wanting nothing to do with Him, as evidenced by our unholy use of His name.
Remember too that as our goal in this entire series is to know God’s love for us and to grow in a relationship of love with Him, might we all consider again our call to eternal communion in His presence – which already began in baptism and remains through His presence with us here and now, especially when we directly call upon Him. Accordingly, may we always open ourselves to him and practice returning our love to Him by always calling upon the Lord in utmost reverence, seeking to uphold His sacred name out of love for Him.
For further reading: In the Catechism of the Catholic Church, paragraphs 2142 - 2167 gives detailed teaching the Second Commandment, including the dignity of names.