A lie is to speak or act against the truth in order to lead someone into error. The purpose of swearing is to convince others that we are not lying. ‘Swear to God’ means to call on God as our witness to the truthfulness of what we are saying. Jesus says that we should never swear to God, or to anything, because everything comes from God. If we are always truthful, there will be no need for an oath because our honesty will be presumed.
Lord, help me to be truthful in the things I say and do.
Reflections on the Word of God 