Verse 1 – The elder, to the elect lady and her children, whom I love in truth, and not only I, but also all those who have known the truth,
Verse 2 – because of the truth which abides in us and will be with us forever:
Verse 3 – Grace, mercy, and peace will be with you from God the Father and from the Lord Jesus Christ, the Son of the Father, in truth and love.
Verse 4 – I rejoiced greatly that I have found some of your children walking in truth, as we received commandment from the Father.
I don’t believe John is talking to a congregation. I think this letter was written to a particular “lady” that possibly held church meetings in her house. Children could be her actual children, students of hers, or those Christians which went to her house for service.
Verse 5 – And now I plead with you, lady, not as though I wrote a new commandment to you, but that which we have had from the beginning: that we love one another.
Some versions of the Bible say, “Beseech,” which is to “urge.” You wouldn’t think that we’d have to be reminded to “love one another.” But, just as an effort has to be put forth in a marriage to love so does an effort have to be urged in a body of believers. Love among believers is a witness to the world.
Verse 6 – This is love, that we walk according to His commandments. This is the commandment, that as you have heard from the beginning, you should walk in it.
John is not talking about personal attraction or preference, but an ethical expectation.
Verse 7 – For many deceivers have gone out unto the world who do not confess Jesus Christ as coming in the flesh. This is a deceiver and an antichrist.
Deceivers were teaching that Jesus was divine but not fully human. Anyone who teaches or believes that Jesus was not fully divine and fully human and the Son of God, born of a virgin, is an antichrist.
Verse 8 – Look to yourselves, that we do not lose those things we worked for, but that we may receive a full reward.
Christians should be on guard and secure their own hearts with the truth of what Scripture says.
Verse 9 – Whoever transgresses and does not abide in the doctrine of Christ does not have God. He who abides in the doctrine of Christ has both the Father and the Son.
John is referring to what Jesus taught which is what He taught about Himself. There are foundations of truth about the Christ all through Scripture. Don’t stray from that! This is only one reason why all other religions are wrong. What we believe has to depend on who we know Jesus Christ to be.
Verse 10 – If anyone comes to you and does not bring this doctrine, do not receive him into your house nor greet him;
Now do you understand why when someone knocks on your door peddling another gospel, you don’t invite them in? If you are not a mature Christian and don’t know God’s Word, you could be persuaded to believe un-truths about Christ.
Verse 11 – For he who greets him shares in his evil deeds.
Verse 12 – Having many things to write to you, I did not wish to do so with paper and ink; but I hope to come to you and speak face to face, that our joy may be full.
Verse 13 – The children of your elect sister greet you. Amen.
If you want to know how so many people can fall for these false religions, and there are many, it’s because they don’t know the God of divine Scripture for themselves. They rely on someone else to tell them what to believe. Know God’s Word and you won’t be led astray!