Do not use the Name of God Frivolously: First, let's go once again to The New Oxford Dictionary, and get a definition of Blasphemy:
"the act or offense of speaking sacrilegiously about God or sacred things; profane talk"
I also want to note one definition of vain: "having no real value; worthless"
As you can see to take the name of God in vain can mean to misuse it in a way that considers it to be worthless. Ways of expressing contempt for God are: first, intentionally by abusing His name or second, unintentionally by simply not considering God at all, the one who is our Creator. To not take the Lord's name in vain one must know who He is and hold Him in the awe He expects and deserves. This can only truly be accomplished by those who are His own.
Therefore, the command is to a people who are supposed to be God's followers, first Israel and secondly, the Church. His name should mean something, and therefore the focus should be on uplifting God, not dragging down His name. This is therefore a command that is universal in application. God created all mankind. Therefore, all are called to a recognition of who He is. All will be held accountable for holding Him of little worth, whether they follow Him or not. Even those who refuse to follow Him will not be excused from trifling with His name.
We can say, then, the command is more than not acting as if God's name were unimportant. But, more important, consistent with the first two commandments, it is really to give God the honor that is His due. In Deuteronomy, Israel was called to honor/worship Him.
"It is the Lord your God you shall fear. Him you shall serve
" Duet 20:10 (ESV)
In 1 Timothy 6:16 Paul says, "To him [Christ] be honor and eternal dominion." (ESV)
And in Romans 1:21-22, he talks of those who refuse to honor the Lord.
"For although they knew God, they did not honor him as God or give thanks to him, but they became futile in their thinking, and their foolish hearts were darkened. Claiming to be wise, they became fools