Many think the third commandment deals only with euphemisms and swearing, but it goes much deeper. It regulates the quality of our worship and glorifying God.
The prohibition against taking God's name in vain is the least understood commandment. When we bear God's name, we are to bear His character and nature.
In the the Third Commandment, God's name describes His character, attributes, and nature. If we bear God's name, we must reflect His image and His character.
To appropriate the name of God means to represent His attributes, character and nature. Our behavior must imitate Christ just as Christ revealed God the Father.
We must put on the entire armor of God, not just the defensive parts. We must proactively rather than reactively assume out part in the spiritual battle.