“And to the angel of the church in Philadelphia write; These things saith he that is holy, he that is true, he that hath the key of David, he that openeth, and no man shutteth; and shutteth, and no man openeth.”
Philadelphia is the youngest of the seven cities in Revelation. It lies in a long west-east valley. By the sea we find Smyrna. After a 53-mile journey, we pass Sardis. Another 30 miles further, we come to Philadelphia. Further southeast (50 miles), we find Laodicea and Colosse. The city of Philadelphia was probably founded to familiarize the people of Lydia and Phrygia with Greek culture (language and customs). Therefore, it is a "missionary city"! But as mentioned in God's Word, it is a missionary city in a very different way.
In the vicinity of the city, there is a lot of viticulture. Dionysos, the god of viticulture, is the main deity. But Zeus, Artemis, and the emperor are also worshiped. There must have been a Jewish community (vs. 9), but nothing of it has been found in excavations.
As each of the seven letters, this letter begins with a self-designation of Christ. Christ is called “Holy and True.” In Mark 1:24, we read how the man with the unclean spirit cries out to Jesus, “Thou art, the Holy One of God.” Jesus is indeed the Holy One in every way. But He is also “True”. He is the True one in the sense of the real Messiah. Therefore, the presumptions of the false (unbelieving) Jews are not pleasing to Him. We read furthermore that He holds the key to the house of David. In other words, He is heir to David's house and kingdom. He possesses access to the true, spiritual Jerusalem (verses 8 and 12). This self-identification of Jesus takes on color when we read verse 9, “Behold, I will make them of the synagogue of Satan, which say they are Jews, and are not, but do lie; behold, I will make them to come and worship before thy feet, and to know that I have loved thee.” This self-designation is a firm rejection of the pretense of the Jews. They think they determine whether and how Gentiles enter, but Christ determines that!
The message from this biblical passage is clear and powerful. We are called to turn to Christ, who is holy and true, and who holds the key to the heavenly Jerusalem. Our own efforts are futile; all that is required is faith in Him.