Ephesus was very religious; it was in their city that the temple of Artemis, one of the seven wonders of the ancient world, was located. Ephesus was in fact considered the world center of Artemis worship (Artemis of the Ephesians) and the whole city was devoted to her. Artemis was the goddess of fertility and prosperity, she was the one, the people thought, that brought the wealth to Ephesus. If you were a man trying to make a living for your family and wanted to be blessed by Artemis you had to make sacrifice to her and attend her festivals. If you were a woman who was pregnant and wanted protection, it was to Artemis you would go and bring offering, many pregnant woman would put figurines of their goddess above where they slept. If you did not participate in the worship, you were excluded from society because Artemis’ followers wouldn't want to associate with someone who may have the curse of Artemis.
The goddess had two festivals, both very erotic. The first was in April, it was called Atremisia and the second celebrated her birthday in May and was called Ephesia. They would celebrate Artemisia by going to the temple and all of the idols depicting Artemis would be brought out and placed on carts and hauled off to the harbor. Once there the idols would be ceremonially washed, representing her restored virginity, Artemis was considered a perpetual virgin. Once the washing was complete the idols were loaded and put back in the temple and the worship of Artemis would begin. There would be chanting and sacrifice but most importantly for the worship service was the engaging in sexual relations between the people and the temple prostitutes. It was believed that in this sexual act was the presence of Artemis, indwelling the “worshipper”. This was Ephesus.
And this is where Paul traveled to with the good news and the message of Jesus. Some scholars say that Paul went precisely to Ephesus because if he was successful there than he could be successful anywhere.