They are puzzled that you do not continue running with them in the same decadent course of debauchery, so they speak abusively of you.
1 Peter 4:4
The world has hated them, because they are no part of the world.
John 17:14
Jesus answered: “My Kingdom is no part of this world. If my Kingdom were part of this world, my attendants would have fought that I should not be handed over to the Jews. But as it is, my Kingdom is not from this source.”
John 18:36
The world is, for lack of a better description, a nasty place. It is a place or thing that Jesus told us not to be a part of. What does this mean? It is further explained if you read the quotes and the before and after of the text which accompanies them. Be attentive to the questions asked and the answers given to garner the truth of what is said. Thus is the Bible understood and not by a cursory reading or snippets derived for argument.