Revelation 3:5-8

5He who overcomes [the world through believing that Jesus is the Son of God] will accordingly be dressed in white clothing; and I will never blot out his name from the Book of Life, and I will confess and openly acknowledge his name before My Father and before His angels [saying that he is one of Mine].

6He who has an ear, let him hear and heed what the Spirit says to the churches.’

7“And to the angel (divine messenger) of the church in Philadelphia write: These are the words of the Holy One, the True One, He who has the key [to the house] of David, He who opens and no one will [be able to] shut, and He who shuts and no one opens:

8‘I know your deeds. See, I have set before you an open door which no one is able to shut, for you have a little power, and have kept My word, and have not renounced or denied My name.