Revelation 3:6-8

6He that has an ear, let him hear what the Spirit says to the assemblies.

7And to the angel of the assembly in Philadelphia write: These things saith the holy, the true; he that has the key of David, he who opens and no one shall shut, and shuts and no one shall open:

8I know thy works: behold, I have set before thee an opened door, which no one can shut, because thou hast a little power, and hast kept my word, and hast not denied my name.