Christians have such a high ethic because of what God has done within their heart that they do not need to make vows to the Lord to keep their word. Christians only need to say that they will do this certain action and they will keep their word. The Bible speaks about lying and speaking the truth in a number of places. In the Old Testament God’s people did at times make oaths to the Lord. But in the New Testament we should not do this, at least on a normal basis. The Pharisees abused this teaching. They would swear to heaven, but as long as they did not take an oath to God, so they thought, they did not have to keep their word. As Christians our righteousness must go past this. Our word must be enough.