Revelation 3:1-3 NIV

[1] “To the angel of the church in Sardis write: These are the words of him who holds the seven spirits of God and the seven stars. I know your deeds; you have a reputation of being alive, but you are dead. [2] Wake up! Strengthen what remains and is about to die, for I have found your deeds unfinished in the sight of my God. [3] Remember, therefore, what you have received and heard; hold it fast, and repent. But if you do not wake up, I will come like a thief, and you will not know at what time I will come to you.