The Puritans of the 18th Century had a wonderful saying, "Love the Lord and use the world." Think for a moment about how that works out. It really should affect your life. Too often we find ourselves "loving the world and using the Lord", don't we? This short phrase seems to be the essence of 1 John 2:1-17.
In 1 John 2, we are told that Christians are passing out of the darkness and the light is already shining within us. That means our sinful desires should be less and less and the light of Christ should be brighter within us each day. Practically, we should be more forgiving and less bitter. We should be more encouraging and gossiping less (if at all). We should be more giving and wanting less and less based on selfish desires. (ex: "I just gotta have it!") We should love God more and love the things of the world less. We should love God more and hate our sin.
How do you know if you are a Christian? This would be a great test. What is fueling that fire in your life? What drives your desire to get up in the morning? What do you find yourself thinking about when your mind slips into neutral? Love the Lord and use the world.