Lydia's Baptism

This is the river spot where Lydia, a gentile female convert was baptized. In the back is also a Greek Orthodox church in her honor (Saint Lydia).
It may be that she was not baptized at this exact spot, but it was just a few hundred meters upstream of town, outside of the city walls. There was no Jewish synagogue in Philippi and it is likely that Jews and others interested in Judaism would meet at this spot.

On the sabbath day we went outside the gate by the river, where we supposed there was a place of prayer; and we sat down and spoke to the women who had gathered there. A certain woman named Lydia, a worshiper of God, was listening to us; she was from the city of Thyatira and a dealer in purple cloth. The Lord opened her heart to listen eagerly to what was said by Paul. When she and her household were baptized, she urged us, saying, "If you have judged me to be faithful to the Lord, come and stay at my home." And she prevailed upon us.  (Acts, chapter 16:13-15)

After leaving the prison they went to Lydia's home; and when they had seen and encouraged the brothers and sisters there, they departed. (Acts, chapter 16:40)

To continue with Paul through Philippi, go to the forum.

How is Lydia's baptism significant for understanding the world of Paul?

Lydia, a gentile convert, is the first female in the Bible that receives specific mention as being baptized. A merchant of fine purple cloth, she is an example of an upwardly mobile woman who converted and provided leadership in the early Christian communities.  Women played an integral role in the early church.  She converts her husband and Paul spends the night with her family during his travels.

source:
Hadjifoti, Litsa. Saint Paul His Life and Work. Koropi, Greece: Micael Toubis Publication, 2004.