It was the least important cities of the ones mentioned in Revelation of St.John. The city was located on the eastern edge of the Ionian civilization. But it had the most difficult task of spreading the Christian faith to the east, outside the Ionian region. Philadelphia, together with Smyrna was considered as one of the distinguished churches out of the seven churches of Revelation about which nothing bad was mentioned by St.John.
Philadelphia means "brotherly love" and it was founded by the king of Pergamum, Attalus II, Philadelphus of Pergamum. He was given the title of Philadelphus because of his love for his brother Eumenes, who was the previous king os Pergamum.
The geographical position of the city was very important. It was on a high hill overlooking the Persian Royal Road and the two important valleys of Ionia, the Hermuz (Gediz) and the Meander (Menderes).
By the year 19 A.D. native language Lydian had ceased and only the Greek language was spoken.
The city was in the middle of the grape country. So, the most respected god was Dionysus. The regional town center of Alasehir still continues the tradition of harvesting grapes.
In his famous letter of Revelation, St.John wrote to the people of Philadelphia :
"(3:7) To the angel of the church in Philadelphia write :
This is the message from the one who is holy and true. He has the key that belonged to David, and when he opens a door, no one can close it, and when he closes it, no one can open it. (3:8) I know what you do; I know that you have a little power; you have followed my teaching and have been faithful to me. I have opened a door in front of you, which no one can close. (3:9) Listen! As for that group that belongs to Satan, those liars who claim that they are Jews but are not, I will make them come and bow down at your feet. They will all know that I love you. (3:10) Because you have kept my command to endure, I will also keep you safe from the time of trouble which is coming upon the world to test all the people on earth. (3:11) I am coming soon. Keep safe what you have, so that no one will rob you of your victory prize. (3:12) I will make him who is victorious a pillar in the temple of my God, and he will never leave it. I will write on him the name of my God and the name of the city of my God, the new Jerusalem, which will come down out of heaven from my God. I will also write on him my new name. (3:13) If you have ears, then, listen to what the Spirit says to the churches!"