1 John 3.1 raises a bunch of interesting questions. The words of the verse are See what kind of love the Father has given to us, that we should be called children of God; and so we are. The reason why the world does not know us is that it did not know him. One of the questions is, "When John tells us that God has "given" (or bestowed) the kind of love that makes it so we are called "his children", how do we understand "given" or "bestowed"? The Greek makes it possible to understand the word as a gift that is given or something that is given in response to a request. Did God give us this love as a gift or has he called us his children because we asked for this gift? The answer to that sends us on a theological trek that I don't want to explore right now.
But there is another question I do want to explore. John tells us that the world does not know us because it doesn't know the father. To which my response is "So what?" So the world doesn't know us, what's the big deal? Now we know that because the "world" didn't know Christ that he ended up on the cross. So if that is what John has in mind here, then it is a big deal. The world doesn't know the Father, so it doesn't know us and the result is going to be persecution. That has some possibilities.
However, I wonder if there is another big deal here, especially for North American Christians. In 1 John 2.15 John has told us that we are not to love the world. The world is about the desire of the eyes, the desire of the flesh, and the pride in possessions (esv). Or putting it another way. A person of the world lives a certain kind of lifestyle where they operate on a purely human level and have no interest in spiritual things. They focus on protecting themselves and find security in their stuff rather than in God. The best picture of this in the Bible is Jesus parable of the man who wanted to build bigger barns, Luke 12.13 “Someone in the crowd said to him, “Teacher, tell my brother to divide the inheritance with me.” 14 But he said to him, “Man, who made me a judge or arbitrator over you?” 15 And he said to them, “Take care, and be on your guard against all covetousness, for one's life does not consist in the abundance of his possessions.” 16 And he told them a parable, saying, “The land of a rich man produced plentifully, 17 and he thought to himself, ‘What shall I do, for I have nowhere to store my crops?’ 18 And he said, ‘I will do this: I will tear down my barns and build larger ones, and there I will store all my grain and my goods. 19 And I will say to my soul, Soul, you have ample goods laid up for many years; relax, eat, drink, be merry.’ 20 But God said to him, ‘Fool! This night your soul is required of you, and the things you have prepared, whose will they be?’ 21 So is the one who lays up treasure for himself and is not rich toward God.”
Now in all of this, this is what I see. Bigger Barns people are those who have no love of God or spiritual things, who are willing to take from another to gain their own security, these kind of people don’t know followers of Jesus because they don’t know the Father. Here's my punch line: Implied in this is a powerful statement about followers of Jesus. They live a distinct lifestyle where their affections are centered on God, they have a deep love for spiritual things and they have a deep concern for the good of others. The words of John speak as much about our behavior as they do about the world. If our lifestyle distinct enough that instead of looking like bigger barns people, our life looks so odd that the rest of the world can't understand it?