297. THE SECOND COMMANDMENT
You are not to take the name of Jehovah your God in vain, for Jehovah will not hold anyone guiltless, who takes His name in vain.
Taking the name of Jehovah God in vain means in the natural or literal sense the misuse of the name itself in all sorts of conversation, especially false statements or lies, and in swearing without good cause, or in order to avoid being blamed, in evil intentions, which are curses, and in witchcraft and spells. On the other hand, swearing by God and His holiness, the Word and the Gospel, at coronations, ordination into the priesthood, or inauguration into offices of trust, is not taking the name of God in vain, unless the one who takes the oath subsequently rejects his promises as worthless. The name of God, being holiness itself, is to be constantly employed in the sacred business of the church, as in prayers, hymns and all forms of worship, as well as in sermons and writings on religious subjects. This is because God is present in everything to do with religion, and when He is duly invoked, His presence is summoned by His name, and He listens. In these ways the name of God is hallowed.
[2] The sanctity of the name of Jehovah God can be established from the name of Jehovah, which the Jews after their earliest period did not, and still do not, dare to utter; and on their account no more were the Evangelists and Apostles willing to use it. Therefore in place of Jehovah they said 'the Lord'. This is evident from a number of passages of the Old Testament quoted in the New, where 'the Lord' is substituted for Jehovah; e.g. Matt. 22:37; Luke 10:27 compared with Deut. 6:5, and elsewhere. It is well known that the name of Jesus is likewise holy, from the Apostle's saying that at that name every knee does and should bow in the heavens and on earth; and moreover that it cannot be uttered by any devil in hell. There are many names of God which are not to be taken in vain, such as Jehovah, Jehovah God, Jehovah Zebaoth, the Holy One of Israel, Jesus and Christ, and the Holy Spirit.