If there were no lies, there would be no need for oaths. But there are many lies, so how can we tell who is telling the truth? In every culture, oaths are solemn vows which bring a curse on the person who breaks them. The idea is that the bigger the authority you put yourself under, the more reliable the statement must be. So people might swear an oath by heaven, implying that heaven would have the right to judge if it was not the truth.

Jesus certainly wanted people to do what they had promised, but questioned their need to make any oath. Every word spoken is heard by God, and He will always be the judge. So there is no need to validate what you say by swearing on anything. Any authority we may swear upon is always going to be inferior to God Himself. So for that reason, swearing is redundant. In God's kingdom, truth is always the currency of communication. So, in heaven, nobody needs to convince anybody that they are telling the truth – because they never tell lies. Swearing is redundant for that reason too.

Swearing often becomes a thoughtless way of emphasising a point – but why, if you are telling the truth? Again it is redundant. But many people simply get into the habit of swearing and do not know they are doing it. It is a bad habit which broadcasts to everybody that you need to affirm that something is true because you often lie! There is no need for God's children to say anything more than 'yes' and 'no'. To swear is to allow Satan to manipulate you. Strong language - but true.

What we say speaks volumes about us. Swearing may be a habit, but it is a bad habit. It needs to be broken by choosing to practise truth and, over time, get other people used to accepting that because we always speak the truth we will always be true witnesses and faithful promisors. That is important; because when we speak about Jesus, He wants everybody to know that the gospel is true and that salvation by grace through faith is certain. At an everyday level, if our lives are submitted to Jesus (who is the Truth), speaking the truth will validate our faith. Alas, the world of work is full of lies and half-truths; the Evil One is at work in the office and school, the factory and university encouraging a web of lies so that nobody can trust anybody. It is the route to misery. Christian: be truthful, whatever the consequences!