Would Lydia have ever heard the gospel if Paul had not gone to the riverside that Sabbath?
No. Had Paul not come to that riverside park on that Sabbath day, Lydia would never have heard the Word. From her viewpoint she was accidentally in the right place at the right time, but behind it was the sovereign God, who opened her heart.
Les explains this as a divine appointment, not an accident. Paul had crossed from Asia Minor into Macedonia because the Spirit gave him the vision to go there. On the Sabbath, Paul went out of the city to a riverside where prayer was customarily made, sat down, and spoke to the women gathered there. Lydia, a seller of purple from Thyatira who worshipped God, heard them, and the Lord opened her heart. Les emphasizes that had Paul not come to that particular riverside park on that particular Sabbath, she would never have heard the Word. From her point of view she was accidentally in the right place at the right time, but behind it all was the sovereign God. Les applies the same principle to someone who thinks they accidentally ran across his television program: it is not accidental; the Lord is in it from start to finish.
And on the sabbath we went out of the city by a river side, where prayer was wont to be made; and we sat down, and spake unto the women which resorted thither.