You Are Not to Take the Name of Jehovah Your God in Vain, Because Jehovah Will Not Hold Guiltless Someone Who Takes His Name in Vain
In its earthly meaning, which is the literal meaning, taking the name of Jehovah God in vain includes abusing is name in various types of talking, especially in lies and deceptions, in swearing and oath-taking for no reason or to avoid blame; and using his name with evil intent, which is cursing, or in sorcery and magic spells.
To swear by God or by his holiness, by the Word or by the Gospel during coronations, inaugurations into the priesthood, and confirmations of faith is not taking God’s name in vain, unless the people who take the oath later reject their promises as impossible or pointless.
Furthermore, because it is holiness itself, the name of God is used constantly in the sacred activities of the church, such as in prayers, hymns, and all aspects of worship, as well as in sermons and books on church-related topics. The reason is that God is in every aspect of religion. When he is ritually called forth by his name, he is present and hears. In these activities the name of God is kept holy.
The name of Jehovah God is intrinsically holy, as you can see by the fact that after their earliest times the Jews did not dare, nor do they now dare, to say the name Jehovah. Out of respect for the Jews, the Gospel writers and apostles did not want to say the name either. Instead of “Jehovah” they said “the Lord,” as you can see from passages from the Old Testament that are quoted in the New Testament but use “the Lord” instead of “Jehovah,” such as Matthew 22:37 and Luke 10:27 that quote Deuteronomy 6:5 and so on.
The name of Jesus is also holy, as people generally know because the apostle said that at that name knees bend and should bend in heaven and on earth [Philippians 2:10]. For another thing, no devil in hell can pronounce the name of Jesus.
There are many names for God that are not to be taken in vain: Jehovah, Jehovah God, Jehovah Sabaoth, the Holy One of Israel, Jesus, Christ, and the Holy Spirit.
from True Christianity, Section 297