Revelation 3:2-3; Revelation 16:15

2 Be watchful , and strengthen the things which remain, that are ready to die : for I have not found thy works perfect before God. 3 Remember therefore how thou hast received and heard , and hold fast , and repent . If therefore thou shalt not watch , I will come on thee as a thief, and thou shalt not know what hour I will come upon thee.
15 Behold , I come as a thief. Blessed is he that watcheth , and keepeth his garments, lest he walk naked, and they see his shame.