Revelation 3:2-4

Be thou watchful, and establish the things that remain, which were ready to die: for I have found no works of thine perfected before my God. 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. But thou hast a few names in Sardis that did not defile their garments: and they shall walk with me in white; for they are worthy.