Paul is going on his second missionary journey with Silas. They begin their journey by visiting places Paul went during his first trip. In Lystra, Paul visited and encouraged Timothy, his new young friend in the faith. Afterwards, through a dream God directed Paul to take Timothy and Silas and sail across the sea to a city called Philippi.
 And on the Sabbath day we went outside the gate to a riverside, where we were supposing that there would be a place of prayer; and we sat down and began speaking to the women who had assembled. A woman named Lydia, from the city of Thyatira, a seller of purple fabrics, a worshiper of God, was listening; and the Lord opened her heart to respond to the things spoken by Paul. And when she and her household had been baptized, she urged us, saying, "If you have judged me to be faithful to the Lord, come into my house and stay." And she prevailed upon us.* 
God loves all people. God works in mysterious ways so that Paul will meet particular people and tell them the good news. Now Paul's goal is to find a quiet place to pray down by the riverside. In the process God leads Paul to meet Lydia, who was a respected business woman in her community. As Paul spoke the Lord opened Lydia's heart to respond to the good news. For someone to believe the good news God must open their heart. Pray that God will open people's hearts so when they hear the good news they will accept Jesus as their Lord and Savior.
Acts 16:13-15 (NASB)