There is some debate about if this letter was written exclusively to the church in Ephesus, or if it was meant to be circulated more widely.
Ephesus had a harbor that was located at the intersection of major trade routes and was a commercial center. It was famous for the temple of Artimis which was considered one of the seven wonders of the ancient world. There's not a lot known about what was involved in the worship of Artimis, but some information is available at this site.
We can find information about the church in Ephesus by reading Acts 19:1 through Acts 20:1. There is also the passage in Revelation 2:1-7. When I read in Acts 19:1-Acts 20:1, I see these things regarding the church of Ephesus:
- When Paul came to these Believers they didn't know yet about the Holy Spirit
- Paul explained to these people about the Holy Spirit whom they readily received
- Paul taught in the meeting place for 3 months trying to make the kingdom of God real to these people
- Rumors were started (it appears by those in the crowd Paul was teaching) about the Christian way of life so Paul stopped teaching in the meeting place
- Paul started teaching out of the school of Tyrannus (more information regarding the school of Tyrannus can be found here).
- Paul taught at the school of Tyrannus for 2 years
- God did powerful things through Paul during this time. Literally garments of his, such as scarves or handkerchiefs, were taken and put on sick people and those sick people were healed.
- Some people tried to cast demons out of man using Jesus and Paul's name and the demons came out and beat them up. This became highly publicized and many involved in witchcraft renounced these beliefs.
- Timothy and Erastus were Paul's assistants during this time. Paul send them on to Macedonia prior to his leave of Ephesus.
- There was a silversmith named Demetrius who made lots of money off selling statues related to the worship of Artimis. He was concerned about the decrease in business resulting from Paul's teaching. He got together a group of other, similar business men, and they started a big uproar.
- The rioting group went into a stadium and were harassing two of Paul's associates, Gaius and Aristarchus. The town clerk finally got the riotous group settled down and the event dispersed by informing them that any concerns they had needed to be handled through the court system.
- Paul met one last time with his disciples and then left for Macedonia.
When I read in Revelation 2:1-7 I see these things regarding the church of Ephesus:
- They were tenacious and did not quit
- They hated evil
- They fell away from their first love in God
- God wants them to come back to loving Him first