Ephesus was a very important city in the Roman Empire. In it was located one of the seven wonders of the ancient world, the temple of Diana, which was about 600 years old when Paul and his colleagues took the gospel there. A far greater wonder, of course, was the existence of a Christian church in the city, a church composed of people who worshipped the living God.
The church became important as a centre of Christianity. Three councils in the early church met there before the city gradually dwindled due its harbour becoming silted up. Today, the city is only a collection of ruins, but it is an interesting place to visit.
The church in Ephesus was probably the largest of the seven congregations. This was not the first time that the church in Ephesus received a letter that is now contained in the New Testament. Previously, Paul sent a letter to the church there, and he also sent 1 Timothy to his friend when he was in Ephesus. John sent his first letter there too, according to early church tradition. So it was certainly a privileged church. Indeed John is said to be buried in Ephesus, as is Mary the mother of Jesus.
Jesus addresses the letter to the angel of the church, as he does in the other six as well. The angel is a symbol of someone. He could be the messenger who delivers the letter, he could be the angel who protects the church, he could be an angel present with the church in its services (Paul refers to such in writing to the Corinthians).
The angel is not facing a rebuke, so it is unlikely that he is the pastor. Instead of facing a rebuke, he is safe in the hand of Jesus. In any case, given that John lived in Ephesus, and given that he was the last apostle, it is likely that he would have been the pastor of the congregation, and he would not have sent this letter to himself.
Jesus begins this brief letter by reminding the church in Ephesus that he walks among the churches (the seven lampstands). Since he does so simultaneously in each, this is a claim to deity, to omnipresence. Perhaps he described himself in this way to assure the Ephesians that he scrutinised all churches and not just one. There is not only a claim to omnipresence here; in addition, there is a claim to omniscience because none of the churches can hide anything from him.
So what did he discover in Ephesus? We can think about that tomorrow.