Simply let your 'Yes' be 'Yes,' and your 'No,' 'No'; anything beyond this comes from the evil one. _Matthew 5:37
There seems to be an ironic element to Jesus’ teaching here, for prior to verse 37 we are told not to take oaths. Well, a simple “let your 'Yes' be 'Yes,' and your 'No,' 'No'” may be just that—an oath. Jesus style of teaching “you have heard it said…” in the sermon on the mount always leads us to an even more radical understanding of the law about which he is teaching. Perhaps Jesus’ message here is not that you shouldn’t take oaths but that every ‘yes’ or ‘no’ in your vocabulary carries an oath behind it. In other words, if you say “yes,” it very simply means “yes.”
Saying “let your 'Yes' be 'Yes,' and your 'No,' 'No,’” is different than saying “don’t say 'no' when you mean 'yes', or 'yes' when you mean 'no.'” “let your 'Yes' be 'Yes,' and your 'No,' 'No,’” forces us into an even deeper honesty where everything we say means what it says. Instead of doing this, we often force people to read between the lines of what we say and/or we use our words as weapons. We use our words with ulterior motive—to breed guilt, contempt, anger, etc. We push people’s buttons by saying what we don’t mean in order to control our relationships. Words are not for power, “Simply let your 'Yes' be 'Yes,' and your 'No,' 'No.'”
Almost nothing is more destructive in relationships than when we use our words for power. Nothing good ever comes from it because what’s hidden always seems, at some point, to be revealed, and then there's chaos. In Genesis 1, God used his words to create, to bring harmony out of chaos. What are you using your words for?