Jesus spoke often to his disciples about the world system with its values and beliefs which are contrary to the system of the Kingdom of God. Jesus spoke of the Devil being the God of this world and even made reference to the Pharisees or religious leaders as being a part of the world system. “You are of your father the devil, and your will is to do your father’s desires. He was a murderer from the beginning, and does not stand in the truth, because there is no truth in him. When he lies, he speaks out of his own character, for he is a liar and the father of lies” (John 8:44).
Later on in the same chapter, Jesus comforted his disciples about being hated by the world. “If the world hates you, know that it has hated me before it hated you” (John 15:18). It is interesting that the main group of people who hated Jesus and his disciples were the religious leaders of that time. Although in their minds, they represented the Jewish religion, they were referred to as being part of the world system.
James wrote about the world system and what it means for people who love the world. “You adulterous people! Do you not know that friendship with the world is enmity with God? Therefore whoever wishes to be a friend of the world makes himself an enemy of God” (James 4:4).
I know the concept of being in the world but not of the world can be a bit confusing for some people. If we can consider that accepting Jesus Christ and living according to the way that Jesus taught us to live is being of the kingdom, then anything outside of that is being a part of the world system.
“Wherefore come out from among them, and be ye separate, saith the Lord, and touch not the unclean thing; and I will receive you” (2 Corinthians 6:17).