The Bible does not forbid taking oaths, acknowledging that in a world filled with liars there are times when they are necessary. Certainly it is not wrong to take an oath when testifying in court, being ordained, or getting married. Oaths are wrong when they are misused with the intent to deceive others, or when taken rashly or flippantly. The Bible gives examples of godly men who took oaths, lists God’s commandments that oaths be taken, and records instances of God Himself taking oaths.
John MacArthur