Do not believe false teachers
5 So now, lady, I want you to do something. I want all of us to love one another. I am not telling you a new rule that you must obey. This is a rule that we had from the beginning. 6 How do we show real love? We show it when we live in a way that makes God happy. We obey his rules. He tells us to love one another, and that is how you should live. You have heard that rule from the beginning.
7 I say this because many false teachers are travelling round everywhere. They do not agree that Jesus Christ was born as a human baby. People like that are telling lies. They are enemies of Christ. 8 So, be careful! Do not believe their lies. Do not lose the good things that we have worked for. Make sure that you receive all the good things that God has promised to give you. 9 Remember the message which Christ taught. Anyone who teaches his own ideas instead of Christ's true message does not belong to God. Continue to believe what Christ taught. Anyone who does that belongs to God the Father and to his Son, Jesus. 10 Someone may come to you and teach you something that is different. Do not receive that person into your house. Do not receive him as a Christian. 11 If you receive people like that as Christian people, you are making yourself the same as them. You also are doing the same kind of bad work.
12 I want to tell you many more things, but I do not want to write about them in a letter. Instead, I hope to come and visit you. Then I can see you and we can talk together. Then we will be completely happy.
13 The believers here say ‘hello’ to you. They are the children of your sister that God has chosen.
1:13John talks about the group of believers who are with him as the sister of the lady that he is writing the letter to. The words ‘lady’ (in verse 1) and ‘sister’ (in verse 13) probably mean the groups of believers in two places.