Our family reading in the Book of James triggered a discussion about promises, commitments, oaths.
I researched the topic briefly and came to this conclusion:
The clarification by Christian lawyer Brent Winters that the correct translation of the warning about oath-taking that Jesus gave in Matthew 5 was that of the excessive or frivolous use of the solemn oath. It is clearly NOT a prohibition against taking an oath, but the wording of the original text says it prohibits the general use of the oath. The Old Testament did, in fact, have oath-taking as part of God's economy, but it was not used in everyday circumstances and usually in very formal situations, with formal verbal expressions, and with restrictions that oaths were not binding if done by a minor or wife without the husband's consent. In the New Testament era, the oath is allowed, but we are reminded again that it is not be used frivolously. Therefore the Christian is in fact allowed to and recommended to take an oath before God in a modern court.