There are two sins involved in this kind of swearing, perhaps three. First there is the sin of using filthy language (see Colossians 3:8). Second, there is the sin of judgement – if I swear about someone that means I have judged them and condemned them – no one swears about the good things a person does! And third, it is possible that these thoughts could be accompanied by anger. So it is quite clear that swearing about someone is a sin in thought or in feeling or in words. At the very least, it breaks the “Golden Rule� of Christianity: Do unto others as you would have them do unto you.

But what if it’s only in your mind? The other person doesn’t even know you had such a thought. This is true, but think about it – God knows, and you know. Now it may be true that the other person will never know the difference, and it certainly better to keep it to yourself rather than blurt it out and hurt someone’s feelings (or start a big fight!), but it would be better still if you never had the thought at all. The damage a sin does to someone else is only half the damage. The other half is the damage the sin does to the sinner him/herself.

A person who swears, judges and gets angry is destroying the beautiful image of God that is in him/her. They are dirtying the purity of the soul God has given them. They are replacing the precious, unselfish love God has created in them with selfishness, pride and ugliness. Of course this is a sin, even if the other person never realises it! It is a sin big enough to keep a person out of the Kingdom Heaven IF they do not repent from it.

A final note of warning: beware of letting such thoughts feel at home in your mind. You may be able to hide them today, but sooner or later, one of these thoughts will slip out of your brain and on to your tongue. You may then find yourself in a most awkward situation! Better to keep the inside clean, and the outside will be able to take care of itself.