"Again, ye have heard that it hath been said by them of old time, Thou shalt not forswear thyself, but shalt perform unto the Lord thine oaths: But I say unto you, Swear not at all; neither by heaven; for it is God's throne: Nor by the earth; for it is his footstool: neither by Jerusalem; for it is the city of the great King. Neither shalt thou swear by thy head, because thou canst not make one hair white or black. But let your communication be, Yea, yea; Nay, nay: for whatsoever is more than these cometh of evil." (Matthew 5:33-37)

Much like the issues of anger and adultery, this portion of Scripture is much more than a teaching about oaths. In fact, I do not believe Jesus is forbidding oaths under very important circumstances. We see God Himself taking an oath as recorded in Hebrews 6. 

"Wherein God, willing more abundantly to shew unto the heirs of promise the immutability of his counsel, confirmed it by an oath: That by two immutable things, in which it was impossible for God to lie, we might have a strong consolation, who have fled for refuge to lay hold upon the hope set before us:" (Hebrews 6:17-18)

And the Apostle Paul clearly uses promise and oath language in Galatians 1. 

"Now the things which I write unto you, behold, before God, I lie not." (Galatians 1:20)

Jesus is refuting the practiceS of the Pharisees once again. Their practice of using God's name to confirm even trivial statements was violating the commandment to not take God's name in vain. 

Similarly, if you have ever seen the acronym OMG, this is exactly what Jesus says is wrong. 

I have taught children for over 20 years so I have had a lot of experience catching children in a lie. 

Invariably, one of them will say, "But Mr. Lowrance, I swear to ...... that I ....." 

My response to them shocks them, if they understand what I am saying. "Are you sure HE is going to back up what you are saying?"

The student feels if they swear then I will BELIEVE what they are saying is true. 

Jesus teaches us two simple truths. Revere the name of God and always tell the truth!