Loving the world
God makes it clear to hate the sin but love the Sinner.
John 3:16-17 For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life. For God sent not his Son into the world to condemn the world; but that the world through him might be saved.
2 Peter 3:9 The Lord is not slack concerning his promise, as some men count slackness; but is longsuffering to us-ward, not willing that any should perish, but that all should come to repentance.
The world here is referring to mankind as a whole. There is no sin that disqualifies anyone from God’s forgiveness except the rejection of the redeeming work of Jesus Christ on the cross. God’s love is unconditional and He will turn no one away who asks forgiveness, repents, and puts their faith in Jesus’s death burial and resurrection. God’s love is what we need to restore the backslidden and reach the lost.
John 10:10b I am come that they might have life, and that they might have it more abundantly.
Not loving the world
1 John 2:15-16 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. 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.
The world here is the world system, which teaches self-centeredness, self-absorption, self-reliance, and self-satisfaction. It removes God from his sovereign throne and replaces Him with them.
John 10:10a The thief cometh not, but for to steal, and to kill, and to destroy:
What the lost don’t realize is that they are the devils slaves and blinded to the truth. What Christians need to realize is that they are servants to the Most High God, who were once blind but now they see.
If you are in the light, why would you want to return to the darkness?