Philadelphia in the Bible

"And to the angel of the church in Philadelphia write: "This is what the holy one, the true one, the one who has the key of David, the one who opens and no one can shut, and who shuts and no one can open, says:

saying, "What you see, write in a book and send [it] to the seven churches: to Ephesus and to Smyrna and to Pergamum and to Thyatira and to Sardis and to Philadelphia and to Laodicea."

"And to the angel of the church in Philadelphia write: "This is what the holy one, the true one, the one who has the key of David, the one who opens and no one can shut, and who shuts and no one can open, says: 'I know your works (behold, I have put before you an opened door that no one is able to shut) that you have a little strength, and have kept my word, and did not deny my name. Behold, I am causing [those] of the synagogue of Satan, the ones who call themselves Jews and are not, but are lying--behold, I will make them {come} and kneel down before your feet and acknowledge that I have loved you. read more.
Because you have kept the word of my patient endurance, I also will keep you from the hour of testing that is about to come upon the whole inhabited world, to put to the test those who live on the earth. I am coming quickly! Hold fast to what you have, so that no one may take away your crown. The one who conquers, I will make him a pillar in the temple of my God, and he will never go outside again, and I will write on him the name of my God and the name of the city of my God, the new Jerusalem that comes down from heaven from my God, and my new name. The one who has an ear, let him hear what the Spirit says to the churches.'