Platonic Dualism: Splitting the Body and Soul. Plato offers the first, oldest argument that one's physical body and soul are separate entities and that one lives on after the other has died. Christian philosophers later picked up on this concept and rationalized it to present a dualistic faith in which one only focused on the spiritual dimension of one's life and ignored the material world, which also included the culture.
This is an important concept for Christians to understand because it explains why Christianity is in such a weak state with regard to influencing the world. Christians that accept this view as their reality will focus solely on the spiritual dimension of the faith. They believe they are not to influence the world in any way. This is especially true when it comes to cultural issues. This is not a valid view of the Christian faith. Just prior to the return of Jesus to the Father he gave Christians the Great Commission found in Mathew 28: 16.
16 Then the eleven disciples went to Galilee, to the mountain where Jesus had told them to go. 17 When they saw him, they worshiped him; but some doubted. 18 Then Jesus came to them and said, “All authority in heaven and on earth has been given to me. 19 Therefore go and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, 20 and teaching them to obey everything I have commanded you. And surely I am with you always, to the very end of the age.” (NIV)
Jesus explained that he was given all authority in both heaven and earth. We are explicitly commanded by Jesus to make disciples of all nation based on that authority. The Great Commission affects all facets of human life, which includes both spiritual and earthly aspects of life. This includes the culture. Jesus taught his disciples that they are both the light and salt of the world. As light we share the Gospel in a dark fallen world. As salt we help to keep the culture and world from rotting morally by extending the ethics of the Kingdom of God into the world. This is reinforced by the words of Jesus when he taught the disciples how to pray.
Matthew 6:9-13 9 “This, then, is how you should pray: “‘Our Father in heaven, hallowed be your name, 10 your kingdom come, your will be done, on earth as it is in heaven.11 Give us today our daily bread. 12 And forgive us our debts, as we also have forgiven our debtors. 13 And lead us not into temptation,[a] but deliver us from the evil one.[b]’ (NIV)
Note how instructed us to pray that his Kingdom come, and that his will would be done on earth as it is in heaven. This contradicts a view of the faith that is solely focused on "spiritual" things to the exclusion of things in the world. In fact, one of the first heresies that tried to derail the early church was the teachings of the Gnostics. They taught that the Christian life only dealt with the spiritual dimension of life and that what one did with their body had no bearing on the Christian's faith. The result was moral lawlessness within the church body which the Apostles had to address right away.
However, that heresy has returned today. Some Christian leaders teach that we are not to be involved in public policy or cultural issues that directly impact the welfare of our neighbors. The famous Christian philosopher Francis Schaeffer called this a false pietism that is not taught in the Bible. He was being too kind to Christian leaders who should have known better. This is the same Gnostic heresy that almost infected the early church. If your pastor has this view - leave that church and find one that teaches the whole counsel of God in the Bible.