It is a sin against the Holy Spirit to stubbornly refuse to learn from other people who know about life in today's world. We can ask them for a drink, as Jesus did at the well in Samaria: he did not hesitate to listen to the Samaritan woman when His own people would have nothing to do with her people under any circumstances.
We have a message for the world; but we need the world too. Without understanding the world we have no relevant language in which to share that message. Moreover, the world helps us understand ourselves better, especially our need to be open to the newness of the Gospel.
We are alive today, not in Paul's time. The men and women we meet have different ideas from those of the Jews and pagans he met in his travels. It is the ideas of today's people, and what is important to them, that must be confronted with the Good News. These values will not be destroyed, but set on fire by the life of the Risen Jesus. Pope Paul VI said: "It is not a good thing to be promised to the world or unite ourselves with its thoughts, customs and tastes; but instead we should study it, love it and serve it."