It is in the Bible!

1. Matthew 24:6
   You will hear of wars and rumors of wars, but see to it that you are not alarmed. Such things must happen, but the end is still to come.
   Matthew 24:5-7 (in Context) Matthew 24 (Whole Chapter)
2. Mark 13:7
   When you hear of wars and rumors of wars, do not be alarmed. Such things must happen, but the end is still to come.
   Mark 13:6-8 (in Context) Mark 13 (Whole Chapter)

   Luke 21:11 (New International Version, ©2011)

   ¹¹ There will be great earthquakes, famines and pestilences in various places, and fearful events and great signs from heaven.