Christians should love the world of people and be concerned for their eternal welfare (John 3:16). This means to have compassionate heart. The command not to love the world in 1 John 2:15 has to do with the world of sin, the universal system organized by Satan against God and His rule. We must never become attached and devoted to the ways of the world. This is what is meant by worldliness.
1 John 2: 15-18
Stop loving this evil world and all that it offers you, for when you love these things you show that you do not really love God; for all these worldly things, these evil desires–the craze for sex, the ambition to buy everything that appeals to you, and the pride that comes from wealth and importance–these are not from God. They are from this evil world itself. And this world is fading away, and these evil, for bidden things will go with it, but whoever keeps doing the will of God will live forever. Dear children, this world’s last hour has come. You have heard about the Antichrist who is coming–the one who is against Christ–and already many such persons have appeared. This makes us all the more certain that the end of the world is near. (KAB)
15. Love not the world, neither the things that are in the world. If any man love the world, the love of the Father is not in him
16. For all that is in the world, the lust of the flesh, and the lust of the eyes, and the pride of life, is not of the Father, but is of the world.
17. And the world passeth away, and the lust thereof: but he that doeth the will of God abideth for ever.
18. Little children, it is the last time: and as ye have heard that antichrist shall come, even now are there many antichrist; whereby we know that it is the last time. (KJV)