“For this is the message that you have heard from the beginning, that we should love one another.” 1 John 3:11
Children of God
There is an expression you may have heard that goes something like "the apple doesn't fall far from the tree", which is usually used to mean that a son is quite like their father in one or many ways. Sometimes it is used to praise someone who has shown virtue, other times it is used to lament how vices are handed down like heirlooms no one wants. John, similarly, calls those who have virtue from living in the love of God, children of God.
As we can see from 1 John 3:1 and again in 4:19, God's love initiates our ability to be His children. God loves us, calls us to become a part of His family, and leaves it to us to respond positively to this call or to reject it. When we accept this call, we are not immediately transformed into a full-fledged twin of Jesus (the perfect son of God). As John points out in 3:2 what we will look like once God's love has completed its work in us is not known. We have only seen God through mediators. One day that will change, and we will be like Him–which is an exciting and terrifying notion.
In the meantime
While we don't know what we will be like in the future, John tells us what the love of God means for how we live now. We are to love one another. At the very least this means we must love those who are within the body of Christ. Some would like us to stop there. At times it seems an insurmountable challenge. However, an argument could be made and perhaps should be made that the child of God should love everyone. This is the view I hold. To paraphrase Jesus: “even the wicked take care of their own” (Matthew 5:47). The follower of Christ, however, is to love everyone. After all, God causes the sun to shine on the good and the bad (Matthew 5:45) and Christ died to save those who needed saving—that is to say, EVERYONE.
The question of how to love
Once one becomes a Christian and understands the need to love, the necessary question of how to love will follow. John anticipates this question and gives the answer: love how Jesus taught to love (3:23). When we love the way Jesus taught (and how he himself loved), it will show that we are the children of God and will keep us abiding in God.
The question of how we can possibly love like Jesus
Knowing that we should love like Jesus will not mean that we will love like Jesus. In fact, simply trying to do so will only lead to the frustrating realization that we can’t. That is to say, the apprentice will never be able to outdo the master so long as they remain an apprentice. Maybe thinking about it this way isn't helpful since it seems hard to believe we will ever reach the same level of righteousness as Jesus–at least not while the world is still unredeemed. Maybe this is why John mentions the bit about not knowing what we will be. However, John does hint at how we can love in the way Jesus did: by the spirit of God within us. Only when we have the spirit of God working through us can we love as Jesus loved. This is the only way we can love our neighbors, love our enemies, and love our brothers and sisters in Christ.
-Joel Fletcher