25 The missionaries continued along this path, taking into account people's hopes and expectations, their anguish and sufferings, as well as their culture, in order to proclaim to them salvation in Christ. The speeches in Lystra and Athens (cf. Acts 14:15-17; 17:22-31) are acknowledged as models for the evangelization of the Gentiles. In these speeches Paul enters into "dialogue" with the cultural and religious values of different peoples. To the Lycaonians, who practiced a cosmic religion, he speaks of religious experiences related to the cosmos. With the Greeks he discusses philosophy and quotes their own poets (cf. Acts 17:18, 26-28). The God whom Paul wishes to reveal is already present in their lives; indeed, this God has created them and mysteriously guides nations and history. But if they are to recognize the true God, they must abandon the false gods which they themselves have made and open themselves to the One whom God has sent to remedy their ignorance and satisfy the longings of their hearts. These are speeches which offer an example of the inculturation of the Gospel. Under the impulse of the Spirit, the Christian faith is decisively opened to the "nations." Witness to Christ spreads to the most important centers of the eastern Mediterranean and then to Rome and the far regions of the West. It is the Spirit who is the source of the drive to press on, not only geographically but also beyond the frontiers of race and religion, for a truly universal mission.
Source: Redemptoris Missio (Vatican.va)