The first reading describes the procedure used by Christian missionaries, including Paul, in spreading the gospel. Usually, they do not go to places where the people have never heard about God. Instead, they travel to towns or cities where others, especially Jews, have already paved the way before them.

Most Jewish missionaries would have instructed the people about God and His laws. These instructions mainly attracted those who were interested in monotheism (the belief in one God) but were not willing to become full Jews.

Traditionally, a commonplace where Christian missionaries preached was the synagogue or "place of prayer". It is to such "place of prayer" in Philippi that Paul goes to on the sabbath day. There, he meets and preaches to some women. A woman named Lydia listens to them "and the Lord opened her heart to accept what Paul was saying". Lydia believes and later, she and her household are baptised.

As followers of Jesus, we are called to witness to and preach the gospel. It is a task we have to carry out daily through our actions and words. However, it is the Holy Spirit who "opens the heart" of the people around us. Human reasoning, enthusiasm and creativity are essential elements in the work of evangelisation. Without the Spirit of the Lord, what we do or say will remain good actions or advice.