Jesus' statement in Matthew 5, "Swear not at all," is located in a portion of His Sermon on the Mount in which He is correcting the false practices of the Scribes and Pharisees. His instruction here means, "Swear not at all (as the Scribes and Pharisees do); swear not at all -falsely, hypocritically, or rashly."

Calling upon God's Name by swearing an oath in His presence is an act of worship. When performed reverently, appropriately, and bindingly, it is an act which publicly calls upon, and honors, the Name of the Lord. Confirming truth and promise by swearing an oath is foundational to order in society and church - it underlies witnessing in court, assuming a public office, entering marriage, making confession of faith, and having one's children baptized. Its use is to be limited to solemn acts of church or state required by those in authority, or to important matters in private life in which an oath is needed to establish a crucial agreement or settle a serious controversy. Frequent or irreverent swearing of oaths, however, is not permitted. This profanes the oath's necessary reverence.

The word "vain" means "empty; void; of no real value, worth or importance." We can use God's Name in vain by ignoring Him and not calling upon His Name for our needs, or by not using His means of grace. In doing so, we treat His Name as vain - of no real value or importance.

Unbelief takes God's Name in vain; it does not trust God for all things; it regards His help as vain.

A careless, light, or flippant use of God's Name is taking it in vain; it lacks the reverence required when using God's holy Name.

Paul frequently skips his personal Bible reading and devotions at home. "I'm just too busy certain days," he complains.

At other times his mind wanders far from God, dwelling upon all other types of subjects during church worship and personal prayer.

How are both his lack of, and mind-wanderings in, personal worship and devotion transgressions of God's third commandment?