Revelation 3:1-3 American Standard Version (ASV)
3 And to the angel of the church in Sardis write:
These things saith he that hath the seven Spirits of God, and the seven stars: I know thy works, that thou hast a name that thou livest, and thou art dead. 2 Be thou watchful, and establish the things that remain, which were ready to die: for I have [a]found no works of thine perfected before my God. 3 Remember therefore how thou hast received and didst hear; and keep it, and repent. If therefore thou shalt not watch, I will come as a thief, and thou shalt not know what hour I will come upon thee.