Why It's Wrong to Take God's Name in Vain
This article explains the meaning of the third commandment in its various parts. It spells out how God's name was far more than just a name, and so any sin against his name is very great.
Are You Obeying the Third Commandment?
What does it mean to take the name of the Lord in vain? This article explains that profanity is not the only concern of the third commandment, but that the honour of God is at the heart of this command.