1 John 2:15 (ESV) … “Do not love the world or the things in the world. If anyone loves the world, the love of the Father is not in him.”
If we are going to walk in the light with the God who is perfect holiness, we cannot sit loosely to sin in our own lives. We have already begun to realize that being a Christian calls for a thorough-going dedication to the will of God. We must actively enter into all that Jesus has made available to us through his death. We shall show the reality of our faith by obedience to God’s will in every part of our lives. This in turn will strengthen and develop the reality of fellowship with him. Now John makes this same point in a different context, as he shows us that if we are going to love God, we cannot also love the world. The two are mutually exclusive as objects of our love.
We must begin by asking what John means by the world. After all the same Greek word (kosmos) is used by John in his gospel, where he tells us that ‘God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life’ (Jn. 3:16). Are we not to be like God in demonstrating that sort of compassion? Yet later in this letter we shall find John telling us that ‘the whole world is under the control of the evil one’ (5:19). It is no wonder that Christians have had very differing attitudes towards the world. Sometimes in the history of the church the emphasis has been upon withdrawal from contact with the world, while at other times the church has been so enmeshed in the world that it has been difficult to see how Christians differed in their lifestyle from the secular society around them.
The fact is that the word kosmos has different shades of meaning in Scripture. Sometimes it stands for the natural world which God has created—planet Earth. This is much the same meaning as in Psalm 24:1, ‘The earth is the Lord’s, and everything in it, the world, and all who live in it,’ although the word kosmos is not actually used here in the Septuagint. The natural world, created and sustained by God, expresses his character in its beauty and splendour. In this creation, mankind has a special responsibility to fulfil the divine mandate to ‘rule over all the earth, and over all the creatures’ (Gn. 1:26). So the ‘world’ comes to mean the whole human race, who are both the apex of the created order and, at the same time, God’s vice-regents. This is the world that God loves enough to send his Son to rescue (Jn. 3:16).
But there is another meaning of the world in the New Testament. Sometimes the world is seen as an organized system of human civilization and activity which is opposed to God and alienated from him. It represents everything that prevents man from loving, and therefore obeying, his creator. This meaning of kosmos has much the same content as John’s term ‘darkness’ in chapter 1. The contrast between light and darkness could hardly be more stark. For John this is developed in a series of contrasts, such as truth and falsehood, love and hate, love of the Father and love of the world. That is why verse 15 is such a direct command: Do not love the world. James reminds us that ‘friendship with the world is hatred towards God’ (Jas. 4:4). Our contemporary danger is that we tend to water down this radical demand. We think that we can love the world a little bit. After all, ‘What’s wrong with it?’
The world glitters and sparkles and draws us towards it; and many Christians, as well as those who are seeking Christ, have discovered that the alternative can look so unattractive, stodgy, and old-fashioned. Too often the community of Christians can repel those who are genuinely open to Christ because it does not adequately reflect his vitality and love. No wonder people ask, ‘If I do become a committed Christian, isn’t that going to be very restrictive and inhibiting?’ The church can look like a black and white photograph from a bygone age in comparison with the world’s multicolour video presentation. And that problem is not new in the twentieth century. John wants us to look to Christ and see that he is the one whom we are to be like, for only in him can we find our real freedom. It will help us to understand this if we can grasp what is involved in ‘loving the world’. 
 Jackman, D. (1988). The message of John’s letters: living in the love of God (pp. 59–61). Leicester, England; Downer’s Grove, IL: InterVarsity Press.