John 15:18 "If the world hates you, you know that it hated Me before it hated you. If you were of the world, the world would love its own. Yet because you are not of the world, but I chose you out of the world, therefore the world hates you."
Since the world hated our Lord Jesus, we who are His disciples will also be hated by those who are of the world.
1John 3:11-13 For this is the message that you heard from the beginning, that we should love one another, not as Cain who was of the wicked one and murdered his brother. And why did he murder him? Because his works were evil and his brother's righteous. Do not marvel, my brethren, if the world hates you.
After the fall of Adam, the wicked will always persecute the godly and it started with Cain who killed his brother Abel. Men became more and more wicked until God destroyed them with the deluge.
Gen 6:5-7 Then the Lord saw that the wickedness of man was great in the earth, and that every intent of the thoughts of his heart was only evil continually. And the Lord was sorry that He had made man on the earth, and He was grieved in His heart. So the Lord said, "I will destroy man whom I have created from the face of the earth, both man and beast, creeping thing and birds of the air, for I am sorry that I have made them."
John 3:19-20 "And this is the condemnation, that the light has come into the world, and men loved darkness rather than light, because their deeds were evil. For everyone practicing evil hates the light and does not come to the light, lest his deeds should be exposed."
So when our Lord Jesus came into the world, the world hated Him because He was the light in the world, and because men loved darkness (evil deeds and wickedness), they hated the light otherwise their evil deeds would be exposed.
John 7:7 "The world cannot hate you, but it hates Me because I testify of it that its works are evil."
John 8:42-45 Jesus said to them, "If God were your Father, you would love Me, for I proceeded forth and came from God; nor have I come of Myself, but He sent Me. Why do you not understand My speech? Because you are not able to listen to My word. You are of your father the devil, and the desires of your father you want to do. He was a murderer from the beginning, and does not stand in the truth, because there is no truth in him. When he speaks a lie, he speaks from his own resources, for he is a liar and the father of it. But because I tell the truth, you do not believe Me.
Though the Israelites then were the people of God, they had gone astray and have become like the world, filled with wickedness and lies rejecting truth. Similarly, many Christians today are serving the devil and will persecute godly brethren who keep His words and practice truth.
John 17:14 "I have given them Your word; and the world has hated them because they are not of the world, just as I am not of the world."
Brethren, therefore, since Christ suffered for us in the flesh, arm yourselves also with the same mind, for he who has suffered in the flesh has ceased from sin, that he no longer should live the rest of his time in the flesh for the lusts of men, but for the will of God. For we have spent enough of our past lifetime in doing the will of the Gentiles—when we walked in lewdness, lusts, drunkenness, revelries, drinking parties, and abominable idolatries. In regard to these, they think it strange that you do not run with them in the same flood of dissipation, speaking evil of you. (1Pet 4:1-4)