We can’t really read these verses without having the Gospel of John, chapter 13:34 in front of us. Here Jesus is with his disciples at the last supper and he gives them a “new commandment” (or in the Latin mandatum novum from which we get Maundy Thursday). The new commandment that he gives in the Gospel of John is that “you would love one another”. This really doesn’t sound like rocket science. Well, it isn’t rocket science. It is a new commandment which Jesus insists that his disciples not just hear but actually obey and put into practice.
Now to I John II, he tells the readers in vs.10 that we should love our brothers and our sisters. Now, take note that Jesus actually goes a step further. Listen to the words of Jesus in Matthew 5: 43 “You have heard that it was said, ‘You shall love your neighbor and hate your enemy.’ 44 But I say to you, Love your enemies and pray for those who persecute you, 45 so that you may be children of your Father in heaven; for he makes his sun rise on the evil and on the good, and sends rain on the righteous and on the unrighteous. 46 For if you love those who love you, what reward do you have? Do not even the tax collectors do the same? 47 And if you greet only your brothers and sisters, what more are you doing than others? Do not even the Gentiles do the same?”
The author then makes a random transition from teaching us a new commandment, to love our brothers and sisters in Christ, to warning us about the anti-Christ. At the end of this warning we are reminded to abide in Christ. Again, this is another referral back to the Gospel of John where Jesus tells us in John 15:4ff that we are to abide in him just as he abides in the Father. It is a great second chapter which reminds us of the very many important lessons that Jesus has taught us.