Know how great the love the Father has given to us, in order that we would be called the children of God, and we are. Through this the world does not know us, because it does not know him. 2 Beloved, you are now children of God, and what we will be has not yet appeared. We know that if he would appear, we will be like him, because we will see him as he is. 3 And all who have this hope in him purify themselves, as that one is pure.
Right off the bat John is going back to one of his main themes, the love of God. This should bring to mind many of the great passages from his Gospel, such as John 3:16, at the same time it should give one a little bit of pause, because the usage here is a bit different. What love has God given to us? The obvious answer is that God’s love was made manifest in the person of Jesus Christ. While this is your classic “Sunday School answer,” it is in fact correct. The only way to be called a child of God is to have the Holy Spirit within us (note Romans 8) and the only way to have the Holy Spirit is to have Jesus.
In order to back up this point, John points out that the world does not know Christians because it does not know Christ (admittedly, the referent of “him” can be either God or Christ, but typically the unnamed object in 1 John is Jesus and very rarely the Father). The world is separate from believers and believers are separate from the world.
Children of God will have a form that has not yet appeared in this place, which is an interesting hint at both resurrection and the resurrection body that Paul discusses in his letters (see especially 1 Cor 15). In fact, when Jesus returns (note the “him” this time must refer to Jesus, so it is very likely that last reference is to Jesus as well) our bodies will be transformed to be like his.
The key, though, is not belief in the resurrection or belief in the new body, rather the key for the believer is being pure. While John often hints at the Jewish and ceremonial understanding of the term, here he wants the reader to understand it as right standing before God. Purity is not about performing the right rituals, it is about being sinless before God in terms of being forgiven and staying forgiven. The last portion of this is what matters here, since John is assuming his audience consists only of believers. Staying forgiven refers back to the earlier part of the letter, in that sin will occur but confession and forgiveness need to immediately follow.
Are you staying forgiven?