Revelation 3:5-8

5He that overcometh shall thus be arrayed in white garments; and I will in no wise blot his name out of the book of life, and I will confess his name before my Father, and before his angels. 6He that hath an ear, let him hear what the Spirit saith to the churches.

7And 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 none shall shut, and that shutteth and none openeth: 8I know thy works (behold, I have set before thee a door opened, which none can shut), that thou hast a little power, and didst keep my word, and didst not deny my name.