In verse 28 of 1 John chapter 2, the author of 1 John urges us to prepare ourselves for Christ's return. Whether we are ready or not, Jesus is coming again. And the first time he came as a lamb, but the next time he will come as a lion. And though the day and time of his coming is uncertain, the reality of his coming is certain.
Jesus said himself in John 14:3, "if I go and prepare a place for you, I will come again and will take you to myself, that where I am, you may be also."
And so it's with that thought in mind, the reality of the second coming that the author urges us here: why not get ready? Why not abide?
Because ultimately, we know we can't be righteous on our own; that only comes from abiding— allowing God to set us in the right direction.