Something similar is going on when Christians try in their own strength to follow Jesus rather than letting Jesus live in and through them. John writes to remind Christians of who they really are so their identity can shape their activity...
1 John 2:7-14
John says that what he's writing is not some new fad or trend but it's the same old God who has been around since forever. Jesus is this God. So he's not new, even though John's readers were new to Jesus. John wants his Jewish readers to know that trusting and following Jesus is exactly the way they can obey the commands of God they've grown up with. Their scriptures point to Jesus because Jesus is the same God who wrote them. So he's not new.
On the other hand, John says, perhaps it IS new in a way because for his first readers, the fresh expression of God's light and love in the person of Jesus Christ was a brand new experience altogether. And the idea that God's Spirit is living in all Christians was a brand new concept too! He says this truth is seen 'in him but also in you'! It's the same God that they had known all along but now a new depth of personal intimacy with that God was available and this would have blown them away. This was the new bit for John's readers. Trusting and following Jesus means that he lives in us!
John then talks about what it means to be walking in the light in terms of loving others, especially other believers and he says anyone who hates their brother or sister is still stumbling about in the dark. Isn't it sad that Christians so often squabble and fall out or judge each other and stay away from each other? Aren't we family because of Jesus? We should ask ourselves who it is that we will enjoy eternity with and then start practicing now! Why should we exclude those whom God has included? Why should we draw lines where God hasn't? Family isn't always easy, but if we're Christians, we ARE family and we should be learning to live like it more and more, refusing to give up on one another. This is part of what it means to be in the light, John says.
John reminds his readers (who are Christians) who they are in Christ so they can live from this knowledge as people of the light. He says Christians are a bit like children, a bit like fathers and a bit like young men:
- We're loved like children because we're forgiven by God
- We're wise like fathers because we know God who knows everything
- We're strong like young men because Jesus lives in us