Shorter Catechism Q. 56. What is the reason annexed to the third commandment? A. The reason annexed to the third commandment is that however the breakers of this commandment may escape punishment from men, yet the Lord our God will not suffer them to escape his righteous judgment.
Commentary: We may think that we are being pious when we misuse God’s name. Other Christians may be deceived by our abusing God’s name. And sins against this commandment may not be addressed by the church or by the State. Nonetheless, God notices when people take his name in vain and he will hold them accountable: “the Lord our God will not suffer them to escape his righteous judgment.”
God does not tell us what the punishment will be, which seems to imply that it is open ended. God is free to do as he chooses. We, however, need to heed the warning, that is, in faith “tremble at the threatenings (WCF 14.2).” It is no light matter to use God’s name for selfish and evil purposes. We should be careful, therefore, to keep this commandment.