2:1 John’s love for these Christians is clear. He speaks as a father to his little children, as a pastor to his flock. He has just told them (more or less) that they’re crazy if they deny their sin (1:8-10). And in fact, the closer you get to God, the more sinful stains his light will reveal in you. But this doesn’t grant you license to sin! On the contrary, John says, I am writing you these things so that you may not sin. John wants his readers to know intimate and joy-filled fellowship with God, which requires confessing sin and turning from it.
When it comes to making tea, some people dip their teabags in and out of the hot water. Many Christians approach their relationship with Jesus like this—dipping in and out of church on Sunday mornings, with little change resulting. Other tea drinkers place their teabags in the water and let them remain. In time, the tea seeps into the water and transforms it. For Christ to influence and transform your life, you must remain in him.
2:7-8 A question naturally arises: to grow in intimacy with God, which commandments do I need to keep? John reduces the answer to one. As will be clear in 2:9-11, he’s thinking specifically of the commandment to love one another. It summarizes the others. John says it’s old and yet new. It’s old because it’s found in Leviticus 19:18, but it’s also new because it’s the governing commandment for the Christian life. Jesus said loving God and loving neighbor are the two great commandments (see Matt 22:36-40). If love has a fresh ongoing effect in your life, all the other commandments will fall into place.
2:9-11 Love has become watered down in our world. “I love chocolate cake.” “I love this dress.” “I love that TV show.” For many people, love describes sentimental feelings. But John will tell his readers in 4:8 that “God is love.” It is part of his inexhaustible nature for the good of the beloved and for his own glory.
When you love your brother or sister, you seek to comprehensively and righteously meet his or her need in a way that brings glory to God. It is no mere expression of feelings but an expression of something higher, something eternal. When this happens, you remain in the light and have no cause for stumbling (2:10). Love for God and neighbor allow you to see clearly and avoid falling into sin.
However, the one who hates his brother or sister is in the darkness (2:9, 11) and, thus, out of fellowship with the God of light. Such a person is blinded and doesn’t know where he’s going (2:11). Walking around in darkness never ends well.