The interesting thing about the way John structures this letter is that he often repeats himself. Unlike the way the Apostle Paul writes his letters (he moves from point A to point B to point C, etc.), John moves from point A to points A+B, then moves on to A+B+C, and so on. This is because the later points assume that we understand and are living out the first point.
In chapter 2, John reinforces the idea of fellowship (from chapter 1) now mixed with the new teaching of obedience.
The first century church faced difficult opposition from a cult called the Gnostics. The term Gnosticism comes from the Greek word for knowledge – gnosis. The Gnostics claimed to possess a secret knowledge – or “light” – that held the key to escaping the material world and entering into the realm of the spiritual.
There were several “false teachers” in the first few centuries of Christianity who tried to merge Christian faith and Gnosticism. In this form of teaching, Jesus was often viewed as a messenger from heaven (the realm of the Spirit) who came to give to his followers secret knowledge about how to escape the body and get to the realm of the spirit. These teachers would then claim to be the possessors of this secret knowledge from Jesus that they could then pass on to their followers.
This form of Gnostic teaching raised many challenges for the early church. But there are two issues with Gnosticism that appear to be addressed by John in this passage: How do we know who has true knowledge of God? and how can I be sure that I know God?
Knowledge = Obedience (2:3-6)
First century people would have assumed at least two dominant ways for coming to know God: intellectually and experientially. Because God is transcendent we can come to know him by reflecting intellectually about all that is beyond our world. Or God can come to us and enter into the world in a way that allows people to encounter and experience him.
Highly influenced by the Greek philosophers, many “teachers” in John’s day would have led people to participate in the life of the mind. To know God, for the philosopher, is to participate in an intellectual dialogue and rigor that allows one to transcend the routine life of matter and chaos.
Others, like many pagan cults, would have been emphasizing knowledge as the ecstatic or even sensual experience of the divine. To know God, for cultic leaders, would have been to have an intense personal experience of the divine.
It may be true that people can think about God and also experience God, but for John, true knowledge (the true gnosis) is in the one who obeys the Lord’s commandments and follows his purposes. Those who claim to know God only know him if they obey his commands and “live in the same way as he lived” (2:6).
The Law of Love (2:7-11)
If knowing God means following his commands, one can almost immediately hear the lawyer’s question to Jesus: “Which is the greatest of the commandments?” John reminds his readers that obedience to God is particularly found in the law of love. “I’m not writing to you a new commandment...” (2:7).
The command to love is not a new commandment for the people of God (read Deut. 6:4-5; Lev. 19:18). Yet, certainly in the life of Christ the disciples discovered a radical newness – a revolutionary expansion – of this law of love. In Jesus, love became new in the extent to which it reached. In Jesus, love became new in the lengths to which it would go. And in Jesus, love is made new in the degree to which it is realized.
You Have Conquered (2:12-14)
"Love is the word that best describes the life of God’s New Age, and we get to taste it and practice it in the present time. That’s why, of course, it’s difficult. It’s so much easier to collapse back into living the old way, the way of suspicion and hatred. But that means going back into the darkness, whereas the life of love means going forward into the light... Love – God’s kind of love – isn’t like that at all. It demands a victory, a victory over the old enemy who does his best work through human hatred. Love shines out the more brightly against a dark backcloth; which is just as well, because that’s what’s there." – NT Wright