'Alert' in the Bible

"I know what you've been doing. You are known for being alive, but you are dead. Be alert, and strengthen the things that are left, which are about to die. I note that your actions are incomplete before my God.

So remember what you received and heard. Obey it, and repent. If you are not alert, I will come like a thief, and you won't know the time when I will come to you.

"See, I am coming like a thief. How blessed is the person who remains alert and keeps his clothes on! He won't have to go naked and let others see his shame."